Since FF has just hit the 2.0 milestone, I thought I'd check in with how the browser's come on and a list of extensions I've found useful. An official list of changes can be found here, and I'd advise reading that because I'm going to gloss over or ignore new features I won't use, such as a spellchecker and phishing protection. These things should prove very useful for the slightly less-technical users that are FF's main growing audience, though.
First impressions are that I'm less keen on the icons and brushed metal toolbars than the FF 1.5 default theme... but I guess this has been done for users familiar with Opera and the new IE7 interface. I don't dislike it enough to change it.
Interface changes include close icons on each tab, which you can thankfully easily switch back to a single close icon at the end of the bar. Type "about:config" into your address bar and hit return, type "tabs" in the search box to winnow the list a bit, then change "browser.tabs.closeButton" from 1 to 3. Whilst you're there, you might want to change "browser.tabs.tabMinWidth" to something smaller than 100 — I've simply set it to 0 so the tabs shrink to as small as possible before scrolling. The scrolling tab bar is another new feature, as is a useful "Recently Closed Tabs" entry on the History menu.
At the top of my FF window I've got the following crammed onto one line of toolbar: Adblock list, Back, Forwards, a bookmark folder, the address bar, Go button and menus. Some people don't like the Go button, but I see it as replacing the Reload one. More people don't like the new dropdown menu (for listing all open tabs) at the end of the tab bar, and you can take a look at this blog entry for ways to change it all if you don't.
If you do a lot of browsing and want to keep more than occasional pages, you might like to look at the Scrapbook extension, which a friend of mine swears by.
And of course I'm still using the Squarefree Linked images bookmarklet, plus one I like to call Make page readable. The latter could probably do with some cleaning up, but it works well enough for what I want.
Overall I'm very impressed with this release of Firefox. You can get it here.
2006-11-07: a couple more settings in about:config that you may also find useful...
"browser.chrome.image_icons.max_size" — set to 0 to disable showing a thumbnail of a large image in a tab as a favicon-sized thumbnail. Although resizing of images appears to have generally improved, this can still cause choppiness in the user interface.
"extensions.checkCompatibility" — whilst Nightly Tester Tools can selectively try to force compatibility with extensions you've already installed, turning this option off will actually remove the compatibility check. Use with caution.