Rich client extension samples contain examples about how to 1. add launcher items to launcher, 2. how to add a sidebar panel, 3. how to add context menus and 4. how to add a web search engine to the Notes search list. These plug-ins work on Lotus Notes 8.0 and 8.5.
Here is a quick demo: http://www.youtube.com/watch?v=9YWlyOxcfCE
Qi Liu is the developer. Niklas Heidloff is only the committer.