We just remodeled with hardwood floors, and the funny thing is, someone combined the Roomba and Swiffer concepts:
http://www.robomaid.com/...and it actually works. Grabbed two at a Big Lots for something under $20 each, and the only downside (versus manual 'swiffing') is the artificially limited runtime.
Well, that and the fact that you can't get the pads retail.