Apparently it’s now officially called Firefox 2 and not two-point-o (2.0), so I’ve dropped the .0 from the title. :P
I usually use the shortcut keys ALT+I, ALT+B rather frequently at a forum I visit to get highlighted text in the post box to be italicised or bolded, but in Firefox 2, this shortcut keys no longer work by default. You now have to add the SHIFT key into the mix, so it goes ALT+SHIFT+I instead. If you don’t want to use the SHIFT key, you can edit two values in about:config (like for the close tab button previously):
Change:
ui.key.chromeAccess to 5
ui.key.contentAccess to 4
Taken from MozillaZine forum.
As for other about:config tweaks, head over to this page and for other Firefox tweaks, check this guide out. ;)