@Sam
If you can't find a colleague from whom you can borrow a Swiss Army knife, then get a large woodscrew (take one out of the furniture f you need to - you've got a screwdriver!), screw it into the cork, and pull it out with a pair of pliers, or lever it out with scissors or a suitably strong tool.

Or jam the screwhead in a door and pull carefully.

*is in an inventive mood*
( K2k6 has a proper job these days, Wed 24 Dec 2008, 10:10, Reply)