Airmouse!!! Bluetooth mouse control on my laptop - byfar one of my coolest show off apps..
otherwise all the standard crap that people have posted - but I use the vuzix iwear av310 16:9 video glasses for my videos while i travel and down time at work..
IRC is another fun app for me to use to stay intouch with my fellow online nerds
Lightsabre app for those need to relieve stress moments..
and Portable wifi network analysis for those i want to hack you moments
