Gmail, Google’s popular Web mail application, is already full of useful features all on its own. But Firefox users can further customize Gmail with a variety of add-ons. Some only change the appearance, while others add functionality that makes Gmail more like a personal planner than just a plain old email application. Let’s take a look at three Firefox add-ons for Gmail.

Extension series

The first extension, GTDinbox, is a complicated collection of helpful and semi-helpful features. GTDinbox author Andy Mitchell claims his add-on is based on the action management method popularized by David Allen in his book Getting Things Done, which is based on the premise that writing down tasks frees a person to actually get those tasks done in a more efficient way. GTDinbox tries to help Gmail users become more efficient by grouping and labeling email communications as projects and task-oriented to-do lists.

Right from installation. GTDinbox runs unobtrusively, making only a few default changes in the appearance of your Gmail screen. One of the first things you’ll notice is an option called “Compose Personal” under the original “Compose Mail” link. Click on Compose Personal and you’ll see a composition screen sans the usual From: and To: entry boxes. It provides a quick way of sending an email message to yourself.

GTDinbox adds a category called “Statuses” to your Gmail labels and places new labels under Statuses called “Next Action,” “Action,” “Waiting On,” “Some Day,” and “Finished.” All of your existing labels go under another GTDinbox-created category called “Miscellaneous.” By using these categories and labels, the extension hopes to help you get your inbox empty. That idea is based on another productivity theory authored by Merlin Mann, called “Inbox Zero,” which states that the fewer items in your inbox, the more productive you are. GTDinbox, Mitchell says, is highly compatible with Inbox Zero.

But how do you use all this to make it a worthwhile add-on? Mitchell has done a good job of explaining a typical process at the GTDinbox Web site. When a message arrives in your inbox, you have to determine if it represents an action that must be taken or a resource. Action messages should be acted on immediately, if possible; if not, you apply one of the status labels. You assign a project label to resource messages to group it with other related communication.

None of these GTDinbox features is unique, meaning that anyone could perform any of these functions with existing Gmail capabilities. GTDinbox simply makes it easier to get started with the GTD efficiency principles. The only unique feature of GTDinbox is the ability to right-click on any message and see a popup summary of its contents. It’s unique, but not that useful, since if you left-click on the message you can see the whole thing.

Overall, GTDinbox does what it is supposed to do, and will probably save you a little time in terms of getting your email organized, but it’s nothing even the greenest Gmail newb couldn’t do for herself.

A less complicated but more useful add-on is Gmail Manager, which helps you keep multiple Gmail accounts straight. To get started, register your Gmail accounts after installing Gmail Manager by selecting Tools -> Addons -> Gmail Manager from the Firefox menu, then click the Options button and add each Gmail account that you want Gmail Manager to keep track of.

The extension places a small icon in the lower right corner of the Firefox browser window. You can right-click on the icon and choose which Gmail account you’d like information for. Gmail Manager logs in to that account and gives you a small popup of statistics that shows the number of new messages in the inbox and in labels, with a small preview of each new message. This makes it easy for the “over the shoulder” email checkers (such as your spouse or children) to quickly check for new messages without disrupting your other work too much. Gmail Manager can also notify you when new messages arrive.

This add-on’s only drawback seems to be a lag time between the actual arrival of email in my Gmail inbox and when Gmail Manager reports that to me — sometimes a delay of several minutes. In spite of that one flaw, Gmail Manager is now a must-have for my household, if only because it keeps the compulsive email checkers at bay so I can get my work done.

Last, and tiniest, is dragdropupload. This little add-on is the simplest of the three, but for me the most likely to stay added to my copy of Firefox. Instead of browsing for the file you want to attach to a message, dragdropupload lets you drag and drop the file’s icon or file name onto the entry bar. This works best if you keep a window open for the directory in which most of your documents and other files reside. There are no options or settings to configure with this add-on — simply install it and you’re ready to save time, keystrokes, and mouseclicks.

There you have it: three add-ons for Firefox that make Gmail more useful, ranging from full-featured to simple goodness. All I need now is a Gmail add-on that will take dictation.

SimpleCenter gets shipped with some digital audio receiver products, such as the Motorola simplefi, and it is also downloadable from SimpleCenter.com. SimpleCenter was originally produced by SimpleDevices, which UEI acquired in 2004 as part of its product line expansion. UEI offers a premium version of SimpleCenter for $30 with a proprietary license; it features video transcoding, some remote access and photosharing, and other sync options that run from proprietary codecs, Hersch says; it can’t be released under the GPL.

“Our focus with SimpleCenter is to give consumers the ability to access all their media and devices,” says Michael Hirsch, director of product development for UEI. “Most of the time they have to use different applications for every device. It’s cumbersome and confusing.”

With UEI’s ongoing efforts to expand and enrich SimpleCenter’s feature set, it began to explore new avenues of research. “One of the things we’ve been struggling with is being able to have access to all the devices we want to support and the ongoing testing that is necessary,” says Randy Fish, the lead engineer for SimpleCenter. “We’ve always been a small team, and it’s not possible for us to test every MP3 player and cell phone out there.” Fish discovered the possibilities of interacting with an open source development community watching what happened with another SimpleDevices product, Omnifi, after it was no longer manufactured or supported. “Some users developed a community around it and they were adding features that we never really thought of.”

UEI thought open-sourcing SimpleCenter might be a way to leverage the interest and participation of developers in the community. “We’re up against some big players with big budgets,” Hersch says. “The idea was, how do we compete against that in a way that gets us a product that’s more in line with what users actually want.” In August of 2006, UEI released SimpleCenter as GPL software and set up a project page at SimpleCenter.org.

Fish had no experience with open source software before SimpleCenter was GPLed; in fact, no one at Universal Electronics had ever worked with anything except proprietary software. “This is a new realm for us,” Fish says. “We’re learning as we go how best to work in the open source environment.”

There has been no shortage of interested developers, Fish says, but the challenge has been to persuade those who make changes or add features to give those changes back. For instance, he says, one developer has written code to enable SimpleCenter to run on Linux, but he just hasn’t gotten around to submitting the patches. “They’re on their own timeline,” Fish says. “Obviously, we can’t force them to check anything back in. But we’re trying to figure out ways to incent them to contribute the code back.” UEI is considering offering small rewards like free universal remotes to entice coders to share their enhancements.

One of the biggest challenges UEI is facing is “having the community know that we’re out there,” Fish says. “Getting them to want to contribute. We’re still working toward that, and just getting the word out there that we are open source is one of the first steps. One thing we did think of that might be hard to facilitate is to have some sort of contest for contributions.” Fish says UEI hasn’t hired any open source developers yet, but the company would consider it. “A contest winner would be a solid candidate” for any possible job openings, he says.

Fish says that UEI will probably save some money on research and development as a result of opening the code, but that wasn’t the initial motivation for GPLing SimpleCenter. “We really just want to throw as wide a net over people as possible. There’s a strong analogy to our core remote control business: we capture infrared codes, but we really rely on end users to provide some of that data back to us.” Hersch adds that having a community surrounding SimpleCenter “allows us time to focus on core features that will enable a better experience. If the community feels a certain feature is important, then someone will add it, or motivate us to add it.”