Based on this question I discovered Priceline's Last Minute offers. You need to pay for it in advance though.
The process is a bit fuzzy and there are obviously no guarantees. Assuming I "request" a travel for the next week when do I get an answer? Is it possible to cancel my request before I get a result?
So I tweeted the source, Priceline to ask them. They just responded, with:
Once you place an offer we search for a travel partner willing to accept your bid. You should get a response w/n 20 minutes.
So you only have to wait around 20 minutes to know whether or not you should go looking for something else.
