If you're using OS X, you can now search for Creative Commons content using Sherlock! Just connect to sherlock://drop.creativecommons.org/sherlock/ccsearch.xml
If you don't have OS X, you can still use our search engine to find licensed content.
More info on the CC blog.
Just a suggestion - could whoever designed the toolbar button reduce "Creative Commons Search" to just "Creative Commons"? It takes up much-too-much real estate; we all know it's a search button (just like the rest). Be a good citizen and stop hoggin' all the space.
Otherwise, good work.