Yes you can, using dimmers for 3 (or more) way circuits.

http://store.homeseer.com/store/HomeSeer-Z-Wave-Dimming-Wall-Switch-Matrix-W16C42.aspx?UserID=3329891&SessionID=ApyftEIGY4ZJ2zuJNFaA

Here is a link that might be useful: dimming switch tables

Thanks davidtay, I figured you would have an answer! Now I just have to ask DH to try to figure that chart out.

A few more questions. We have recessed cans that are 25 years old. Should we buy new ones? The Cree LED's fit in standard cans don't they? Or the Juno Wheat Haze trims I have heard so highly recommended-should we buy those? Its so confusing...

You can get multi-way dimmers @ either Lowes or Home Depot too.

I don't see why you need to replace the cans if they are working just fine, unless you're moving them/ replacing significant portions of the ceiling and are subject to laws such as title 24.

There's very little that can go wrong with a standard incandescent can.

Get the screw-in base LR6/ CR6 as they will easier to fit into the standard 5"/ 6" incandescent cans.