A remotely-controlled whiteboard is one of those hacks that seem vaguely pointless at first but, as you think about them, you start coming up with plenty of uses. Leaving messages or reminders for people at home or in other offices, perhaps, or teleworking with distant colleagues. After watching Jeroen Domburg's video of his hacked whiteboard in action - that uses a webcam and the mangled entrails of an old scanner to accomplish remote sight and local control, respectively - I've decided that my life isn't complete without one.
The pen is locked into a perspex carriage, that uses an electromagnet to control whether its tip is against the whiteboard or held away. While relatively slow, the stepper motors from the scanner do allow for some impressive accuracy; if anything it's likely to be your mousing skills that leave the eventual drawing looking untidy. Presumably it would be possible for the system to accept hand-drawn images, but right now it looks to be text only.
Best of all, Jeroen will even let you try it out yourself. In use it's just a case of clicking on the screen where you want the text to be, typing it and then watching the pen do its thing. Test for yourself here: http://sprite.student.utwente.nl/wb