Ive been digging around a few sites and I found a handy tip for searching in Firefox. its done through the address bar and is pretty useful if you search places with a built in site search like torrent sites, youtube etc.
If you go to this link
Viddler.com - Firefox Search tip - Uploaded by melvbot
Ive done a quick screencast on how its done, the video is best viewed in full screen so look for the four arrows in the controls and it should be decent quality. if I havent explained anything clearly enough feel free to ask.
Ooops, video problem. I'll put the link in when its fixed.