- HyperWords extension for FireFox: allows you to highlight any word or phrase on the Web page you're reading, and with a right click immediately search in Google, Wikipedia, Google Images, and other common programs.
- Unit conversions via Google: I used to like doing unit conversions, but a few decades of them and they get a little tiring. Plus, you can make stupid amd embarrassing mistakes. But I may never change another unit without Google. Simply type in it
9.8 m/s/s in lightyears/year/year
and it tells you 1.03. I have yet to come across a unit conversion it can't do.