I lived in Märsta for 3 months once. Nice little town and the people were fairly friendly even though I didn’t speak Swedish. Really close to the airport and the train and very easy to get into both Stockholm and Uppsala from here!
Märsta is a suburb of Metropolitan Stockholm, and the seat of Sigtuna Municipality in Sweden. Märsta has 22,548 inhabitants out of a total 36,937 (Sep. 2006) for the whole of Sigtuna Municipality.
http://en.wikipedia.org/wiki/M%C3%A4rsta