Lately I have been learning my way around different methods of anonymity and exploring the darknets. Been hanging around in the Telecomix IRC anonymously through i2p.
I've also been planning out something related to RFID. The plan to have a series of scanner "checkpoints" at places I know my friends frequent. Using innocuous-looking items such as a keychain, I'll be monitoring their movements through RFID. It is just for fun, and afterwords I'll reveal my trick to them.
I recently followed a tutorial on Instructables to make a hidden data storage that uses an empty phone jack that has a a flash drive connected to it. You have to soldier together an rj-11 and USB cable. Then just plug the new cable straight into the wall to access secret files. http://www.instructables.com/id/Hidden-USB-Storage/
That is about it I suppose.