Every so often, Lifehacker rounds up Firefox add-ons that are too new for official approval, but seriously neat-looking. This batch can automate download management and image uploading, queue up MP3s, and manage Gmail tasks anywhere. The extensions we're pointing to here are both unapproved by Firefox's maker, Mozilla, and require creating an account or logging into it, so standard use-at-your-own-risk warnings apply. That said, many experimental extensions are just waiting for a final go-ahead from Mozilla, and can be pretty darned useful.
This one's a bit rough at the moment, but a true boon to Gmail geeks. If you're using Gmail's tasks to manage to-dos and email duties, gTask Sidebar simply loads the task list—normally popped up in the corner or as a stand-alone window—in the Firefox sidebar. Unfortunately, it doesn't resize it for optimal display over in that corner, and those with really long task lists or even short ones might not like having the control buttons put so far down from the tasks themselves (I doctored my screenshot a bit to show you all the elements at once). And gTask Sidebar only activates as a status bar link—a keyboard shorcut, or even just toolbar button, is sorely needed here. But taking your Gmail tasks anywhere you go on the net is a helpful hack, and that's delivered. Now Google fiends just have to choose between this one and our other favourite sidebar tweak, gDocs Sidebar.
Don't bother powering up GIMP, Photoshop, or even Paint .NET to simply resize your party photos for Flickr, Facebook, or wherever else you drop your JPGs. Shrunked detects when you're being asked to submit a photo, then jumps in and offers to resize it to a few bandwidth-friendly dimensions, or a custom set of dimensions. The catch is that it only works with straight-up file uploads, not the increasingly common Flash-based multi-file uploaders. Still, most photo-friendly sites offer links for "normal" or "simple" uploads, and Shrunked is all over those. Great for saving yourself time (and battery power) with on-the-go uploads, or just getting your preferred image sizes online without any other software.
This one's a bit rougher than the others on this page, but what it does is essential for music hounds. From the Tools menu or a button you install on your toolbar (right-click and hit "Customize"), Play Them All looks for all the MP3 links on the page you're looking at, creates an .m3u playlist that most capable music players (Winamp, VLC, Songbird) can handle, and then passes it to you in Firefox to open or save. In my test, the file looked like an MP3 in the download window, and saved as a ".part" file. Still, by pointing VLC to it, I got a multi-track stream of every track on a certain test page stuffed with music. If that sounds like a system you can handle, it's a lot more convenient than manual track queuing—but be aware that Songbird can create track playlists from any page, too.
We saved the best for last. This little guy cries out for official approval, along with maybe some integration into the core Firefox build. Basically, it lets you create rules for certain file types (*.jpg, *.doc, etc.), from all domains or just certain ones, and tells Firefox where to put them when you download them. So if you want all the Excel spreadsheets from a project site to always go into your "Smith Project" folder, tell it to Automatic Save Folder, and you'll never have to hold Firefox's hand again to get it there.
But let's say you get the rare .ppt from your gmail that you don't want to drop into My Documents/Presentations? Automatic Save Folder gives you a last-chance opt-out at the bottom of your downloads window (pictured at right). The add-on supports regular expressions, for those who can roll with that kind of advanced geekery, and it's a perfect complement to DownThemAll.
Tell us in the comments about any other great experimental extensions you've found recently in the wilds of Mozilla.