When business and upscale travel is down (as it is now), you can get great deals through Priceline's opaque-bidding feature at high-end hotels in big cities — what Priceline calls four-star hotels. For the uninitiated, Priceline.com allows you to bid low prices on a hotel room — with the catch that you don't find out the exact property you booked until your credit card is already charged. Similarly, Hotwire.com shows you a price, but you don't know the hotel's name until after you've committed. (Travelocity.com has begun doing something similar with its Top Secret Hotels function.) Either model is an easy way to get half or more off the rack rate, so long as you don't care about the exact location or brand.