Is there a last.fm app for iOS to submit the music I'm listening to ? Is there a last.fm app for iOS to submit the music I'm listening to ?

Now with iCloud I'm not connecting my devices anymore by cable to the mac, so the tracks are never submitted.

thanks
iScrob seems to do what you want on the iPhone. I found after a very brief search, used it for an hour or so after answering this question and found it to be pretty neat. 

With iOS 5 I can see the track I'm playing in the lock screen and control iScrob as I would Music. 



It also displays album artwork on the lock screen:



The only disadvantage is that I can't create Genius playlists.