Foobar2000 has got a new scrobbling plugin which (is also available here and) is able to scrobble streams you listen to. This was not possible with last.fm before. I gotta say I really like it and since I somehow can't scrobble with the main last.fm program anymore I glady use this.
The last.fm team is working on a last.fm client which is able to directly scrobble the tracks you have listened on your iPod. The only requirements are a working iPod and iTunes. The feature is available in the current beta version of last.fm. I tested it and it works like a charm.