In case someone is about to print some large-scale map, the poster printing service I'm using is (www.posterjack.com) currently running a 15% discount. You just need to enter this code at checkout: Sommersonne2011.

Not sure this works in the non-German version of their shop, but I guess it's worth a try. Profantasy does their convention posters at Posterjack, and the quality is excellent.