Awesome site forfinding out the cheapest dates to fly in Europe. It interrogates all prices and dates for airlines such as Easyjet, Ryanair etc. Really love the bar chart it draws of price against date in the monthly search. The weekend option is cool as well showing you the cheapest places to fly to over next few weekends.
I wonder when Ryanair will close it down!
Here should be an image of flights to Krakov
Cheap Flights to Europe
and the best yet it does a RSS feed of latest offers etc
Thanks to Wandalust for the link