Google Reader Tools
A whole box of tricks for Google Reader — a toolbar button to check your account for unread items, ways to change the appearance of Google Reader, and even open feeds in Google Reader instead of with Safari.
v1.0.1: Safari 5.1 compatibility.
Qwantz Secrets
Qwantz Secrets shows all the Dinosaur Comics secret texts when the pointer hovers over the comic. See here for how to enable extensions (Safari 5 only).
v1.1: Fixes the extension for the new Qwantz layout.
If you own an iPhone or other iOS device, you might also be interested in trying out the QwantzReveal bookmarklets…