Yapta, Travel price tracking.

A very good site that came to my attention is Yapta. Yapta is a tracking site for hotel and air tickets prices. Except from that you can use it as an integrated travel search machine.

I have used it for tracking air-tickets prices. You can search for a specific flight, apply filters such as amount of stops, air-companies, price range etc. and when you find the one suites you, ask Yapta to track it and inform you by e-mail for drops of the price.

I haven't yet found a bargain but it seams promising. Anyone out there who uses it?