I dunno if I "learned' German, but I know enough to get by.. My method however was prolly quite unique...
We had a really cute german exchange student at my school, so I learned German talking to her at lunch and hitting on her... Then I picked up Coles German for Travellers or something like that... and also a german-english pocket dictionary.. which I read whenever I'm bored.. then I started finding people from germany on ICQ and MSN.....