@erikvold
Google Reader Widget + Panel Jetpack for Firefox 4
I was doing a little hacking on the Add-on SDK a few weeks ago and whipped up a simple add-on for Google Reader which demonstrates a typical use case for the widget and panel modules which are part of the addon-kit package which comes with the Mozilla Add-on SDK. I call this add-on GReader Panel, and it basically just creates a clickable widget (which is just an icon that you can put anyplace that a toolbar item can go), which when clicked will open/close a panel about the size of a iPod screen with Google Reader mobile.
If you're interested in seeing the code, it's available on Github like all of my open source work.