User Scripts
Install these in Chrome, Safari, or Firefox with Greasemonkey.
Twitter avatar in menu
See which account you're logged in under at a quick glance
Readable Reader
Compact styles for Google Reader
Readable Trip Advisor Forums
Clean styles for Trip Advisor
Readable Flickr
Legible (large-font) styles for Flickr
Auto Login
Probably not useful for anyone else, this script will determine whether I'm logged in on certain sites. It then automatically navigates to the login page and, once my browser has auto-filled the fields, signs me in.