I was doing some work yesterday, and realized how much more painful it would’ve been without various extensions in Firefox. So I thought I’d eulogize some of my favorites.

Tab Mix Plus – Gives you near-complete control over how tabs function. Whenever I use a Firefox installation that doesn’t have Tab Mix Plus, or that has it set up significantly different from mine, it drives me insane. I can’t even imagine not using it.

Del.icio.us Bookmarks – This does two things. First, it adds a “tag” button in your toolbar which lets you quickly bookmark any page on del.icio.us. Second, it replaces Firefox’s default bookmarks with your del.icio.us bookmarks, so now when you bring up the bookmark sidebar, you can browse or search your del.icio.us bookmarks right there. I’ve used del.icio.us for a long time, but sporadically, so I’d never be sure if I bookmarked something there or not. Now it’s the hub of everything I’ve ever looked at that I think I might want to ever look at again.

Picnik Image Editor – Picnik is a great little photo-editing site which can do all the basic stuff–resizing, cropping, color balancing, brightening, and even several effects like sharpen, blur, sepia, black and white, etc. It’s lovely for doing basic things to photos without having to open Photoshop (and it imports from and exports to both Picasa Web Photos and Flickr). With the extension, you can take any picture off a webpage, or even the entire page, directly into Picnic and edit it. I needed a screenshot of a webpage one time to send to technical support–no problem. I often grab photos from Amazon.com, but they have an annoying white border–no problem; I can fix it before I even download the photo.

Split Browser – This gives you the ability to split your browser into various panes, in any configuration. It’s indispensable for copying non-cut-and-pastable information from one site to another, or for keeping instructions visible at the same time as you’re carrying them out in another tab. My fingers used to go numb from Shift-Tabbing back and forth between tabs, but no more.

Text Link – This is an example of how the simplest little thing can be such an improvement. Text Link recognizes URLs on webpages even if they aren’t marked up as links, and when you double-click on them, it opens them as if they were marked up as links. Without it, you had to copy the link, paste it in the address bar and hit enter (or click go). Which doesn’t seem like a whole lot, but even a little bit of improved ease of use goes a long way.

And a few I love, but I’m not sure I couldn’t live without them

Zotero – Zotero is a research tool which captures citations from all sorts of sources (being a browser-based tool, it’s particularly good at internet sources and electronic journals and things, which a lot of other bibliographic citation tools are not), but in addition to being a citation manager, it also lets you make notes on the various citations and tag and categorize everything–plus, full text search. The only downside is that it does suck a lot of memory; I sometimes wish it had a standalone client for managing citations and notes, with the same level of browser integration for pulling citations from the web. I’m still looking for my perfect combination citation manager/note taking application–if anyone has suggestions, I’d be glad to hear them.

AdBlock Plus – I struggle with this one, actually. It blocks ads on pages, which is nice from my point of view, but not really very nice from the advertiser’s or the website’s point of view, who depend on ad revenue to keep running–and, to keep it free for me. So, yeah. On the other hand, every time I turn it off for a while, I end up turning it back on to keep my eyes from bleeding at those brightly-colored flashing ads that so many websites insist on using.

Context Search – With this installed, right-clicking on any term on a page will let you search for the term in any of your pre-defined search engines. Like Text Link, this is something that could be done with a few more keystrokes or mouseclicks anyway, but if you can make it easier and faster, why not?

Firebug – If I ever do any serious web development, this will likely move into the “can’t live without” category. It displays all the code on a give page and points out errors, etc. I tend to use it now rather than “view source,” because of the way it separates out all the elements so you can easily see them (plus, when you mouse-over the element in the firebug console, it highlights the relevant part of the page, making it ridiculously easy to tell what does what).

Fullerscreen – Hides everything except the actual window you’re looking at–toolbars, menu bar, even the taskbar. If you need the browser toolbars, you can mouse to the top or bottom to make them pop back out. This is great if you have a lot of toolbars (like the bookmark toolbar, and the StumbleUpon toolbar, and the Yahoo toolbar, and the Google toolbar), or lots of tabs open in layers. Sometimes it’s nice to just see the page you’re looking at and nothing else, and have to do less scrolling.

StumbleUpon – Speaking of StumbleUpon. I’m not really a part of the StumbleUpon community, but I do find the toolbar a really interesting way to find new sites. It’s one of the first places I go when I get bored of the internet I know and want to find some places I haven’t found yet. Some of my favorite videos and humor sites I’ve found this way.

So how do y’all have your Firefox tricked out? If you don’t use Firefox, I’m…sorry. Deeply.