Yes, it can be done, however you'll have only one dimmer and it will have control of the brightness, regardless of which switch turns the light on. That can be a bother.
I believe it's possible to build real 3-way dimmer switches, but I've never seen them available. They would be expensive and would require extra wiring.

[This message has been edited by rpxlpx (edited March 25, 2002).]

If you want to dim from all three locations you can get the Lutron Maestro master dimmer and two remote location dimmers. Or the lutron Faedra master and two remotes. They are a bit tricky to install but if you have a little electrical knowledge it is doable. I have the Maestro in my house on a stairway and they are great.