When I use Rhythmbox, I see the currently played song in the sound notification area, is there some way to get the song that is playing on last.fm there?
I currently use the official last.fm program.
I can't say for the official Last.FM player, but I know that Tagplayer (a very popular dedicated last.fm player) supports this. Also Rhythmbox has a last.fm plugin by default. Playing last.fm streams through that should also use the sound menu.