well, if you have an iPod, check out the system from Monitor Audio that goes for only $150 on AudioAdvisor right now. Yes, detachable speakers, and very good reviews.
If you are not goint the iPod route, you could build a system arround Sonic Impact Supter T-amp and some sensitive monitors.. quite portable and could be battery powered if you could find a decent portable CD player.
If you are not goint the iPod route, you could build a system arround Sonic Impact Supter T-amp and some sensitive monitors.. quite portable and could be battery powered if you could find a decent portable CD player.