This page lists the Ubiquity commands I created:

Command (click to install) Description Compatibility/other information
(view source)
Converted Jesse Ruderman's "zap" bookmarklet to an ubiquity command. Removes various annoyances from a web page: plugins, colors, cheap effects, event handlers, and timers. Should work with both 0.1.x and 0.5.x.
Invoke menu item
(view source)
Easily access any Firefox menu item using keyboard (mostly useful for Mac OS X, where focusing the menu is a royal pain.) Should be compatible with 0.5
Insert user agent
(view source)
Inserts the user agent string in the focused text area. Should be compatible with 0.5