One of the best design patterns popping up in mobile applications right now is the sliding "navigation drawer" pattern.

There is great coverage of the advantages of using this pattern on the Android developer site and on Android UI Patterns. Mocking up the pattern in Fluid UI takes a little creative thinking, but it is possible to do it pretty quickly using "half off page" widgets to create the following effect.

drawer pattern showing linking between pages in fluid UI

We've also gotten great feedback from people using other "half off page" widgets to create really interesting design effects - we'd love you to post any interesting ideas you have here!