A stealth startup called Yapta (Your Amazing Personal Travel Assistant) will soon let you not only track price changes on specific flights, but it will also help you get a refund for flights where the price drops after you've already bought the ticket.
Drei Meta-Preisvergleiche: 1) Preisvergleich "Alle Airlines": Preise der günstigsten Reisebüros und Billig-Airlines 2) Preisvergleich "Mietwagen" 3) Preisvergleich "Billig-Airlines", nur Billig-Airlines