You already know you can open a link in a background tab by clicking it with your mousewheel, but the TechMalaya.com site points out five other mousewheel Firefox tricks that you may not have known. Like this gem, which requires a change to
Change the value of
middlemouse.pasteto true. This will let you paste a clipboard content to any text field with the middle mouse button.
Using this tweak coupled with our beloved AutoCopy extension, you could select text on-page and paste it into a textarea (like in a comments response) with a simple click, drag, and mousewheel hit. (Update: Oh, duh. If you’ve already got AutoCopy installed, mousewheel paste is already an extension option.) See more of our favorite Firefox 2 about:config tweaks.