aday

This is one of my favorite Firefox add-ons.

It’s like Quicksilver on the Mac for the browser. It allows you to search terms in Google, dictionary, wikipedia, send emails, convert selections to pdf, rich text or html and is further extensible via command feeds. You can even search locations via Google maps and photos Flickr. You can do all this without leaving your keyboard.

If you use shortcuts or just plain find it easier to do things without having to reach for a mouse sometimes, give Ubiquity a shot.