A quick warning for those who use the S3 Firefox Organizer in Firefox on Windows and are contemplating upgrading to the new Firefox 3.6: S3Fox does not yet work in Firefox 3.6 and is automatically disabled when you upgrade.
UPDATE: S3Fox has now been updated (v 0.4.9) to support Firefix 3.6 (8-Feb-2010).
I got bitten by this issue with my last blog post since I'd updated my main machine with Firefox 3.6 on the day of release. Luckily I hadn't upgraded my laptop and so was able to use that one's S3Fox to upload the image from the post.
Xmarks, Firebug and FireFTP, the other Firefox add-ins I mainly use, all seem to work just fine. I dare say a fix for S3Fox will soon be available.