shell-fm is a lightweight, console-based player for Last.FM radio streams.
It's pretty small (the binary is currently a little smaller than 60K, or
50K when stripped) and it has most features the "official" player has, if
not even a few more. Additional features are, for example:

network interface (control shell-fm remotely) 
autoban (automatically ban all tracks of an artist you don't like) 
bookmark stations (quickly jump to bookmarked stations with a single key) 
... probably more

*NOTE: Last-FM have changed their API so that only PAID subscribers
can listen to streams in shell-fm.