I think that Evilsizer has been messing around with some Atoms. I don't remember exactly how well they crunch, but I do remember it was much better than a P3 could do. Look around in here and I bet you will find his thread on it.
On another note, the new AMD offering coming up might be worth looking at too when they release it. The processor isn't in the same power efficient class as Atom but as a platform it might be competitive in efficiency and it is supposed to be a cut down derivative of the present A64 I believe.