I just bought a set of Crank Brothers Mallets. They have the crank brothers egg-beater style cleat engagement doohickey in them, but are also bearable to ride in regular tennis shoes, so I can ride the bike to places and still be able to walk around.

I'm not sure if I'm going to actually use them as platforms for riding to work, but I rode it to dinner yesterday, and it worked pretty well.

Edit: I did feel hugely down on power, though. Stretches of road that don't seem hard on my Cervelo with clipless seemed like a struggle on the other bike with platforms.