I have been told that loosening the crank bolt and riding the bike around the block will loosen the crank enough to pull it off (the taper of the spindle encourages this).
Of course there is a _very_ good chance of ruining the interface between the crank and the spindle by riding with loose cranks!
Chuck Schmidt South Pasadena, Southern "beautiful warm fall day" California http://www.velo-retro.com (reprints, T-shirts and Campagnolo Timeline)