The shells of Rotodrum drum kits are cut in half and height-adjustable to "change the spirit of the sound." This design lets you for instance turn shells into triggers, or test new mic setups for recording.
Other demo videos are available online on http://www.youtube.com/user/rotodrum and you can get more details on http://www.rotodrum.com.

http://www.rotodrum.com/drum.html
http://www.youtube.com/user/rotodrum