Yep, the mileage run section on FT is great, but primarily if you're US-based. There other deals on there too, however, so it pays to check it out from time to time.

Two other websites that might interest you are "Secret Flying" and "Fly4Free".

Then there's also Pelikan.sk. This website is Slovakian, although somewhere there was once an English flag to click on to translate it all into English. In any case, if you can work out the city names, it might help to get you started - check the dates and flights and destinations against IATA, for example. There are often some good intra-EU and ex-EU flights advertised.

Aside from that, keep an eye out on the frequent flyer blogs around here which often list mileage runs and the like.