I recently added some extensions in FF and TB that are pretty cool. I thought I'd post about them here in case anyone was interested...
Old Default Image Style 1.0 - FF - This extension reverts back to the older style "view image" in Firefox. The newer FF centers the image on the page with a black background. In older versions, there was no centering and the image was on a plain white background page. I'm talking here about when you RIGHT click on an image on a website and choose "View Image" from the context menu.
Theme and Font Size Changer 5.3 - FF and/or TB - This extension allows you to change the colors, fonts, and font sizes within the FF and TB interfaces regardless of the settings of your desktop/windows manager.
QuickFox Notes 2.7.3 - FF and/or TB - This cool little extension adds a note pad/sticky note application to either your FF or your TB. I use it in TB for everyday "don't forget the milk and bread" type notes. It's pretty cool, I think.
Have FUN!