I would recommend checking Hotwire's rate against the cheapest hotel rate. I stayed at the Venetian this past weekend and with Hotwire's "double the difference" guarantee, it was basically free. The hotel website rate was around $200 and Hotwire wanted around $475. Double the difference for two nights was credited back. I've had this happen many times when the Hotwire rate was hundreds more than the hotel's own website rate (the best was when the downtown Raleigh, NC, Sheraton had a rate of $69.00 and Hotwire had a rate of around $400.00...I made major bucks on that one). Just make sure you read the rules and take a screenshot of the rate when you find it (after you book it at hotwire). The hotel rate jumped up to $399.00 12 hours after I booked on hotwire, but they honored the screenshot rate.

I thinks there is a limit of $1000.00 per six months you can claim.