This is an interesting thread since just this past summer we had the opportunity to take a portable ipod player with us on the road. It was used far more heavily than i ever figured it would and as i'm thinking about this, it also got great use in the hockey dressing room during a tournament in Banff back in March.
We don't use the ipod much, but for travel it is a great way to take alot more music along than via cds, and with the right application, we could upload mp3s in high quality formats for playback (in the event it got plugged into a better system).
The convenient options of the portable (Logitech) player was the fact it could use batteries or be plugged in (not everyone's dock or beach has power outlets).
The bass boost was nice considering the unit was so small. It made it sound alot less like a cheap AM radio.
It also had a stereo plug in the rear so one could hookup other electronics. In our case we watched a movie on a laptop down by the dock but got sound from the Logitech instead of the tiny laptop speakers but hooking up the headset out to the Logitech in port.
Obviously it would be nice to have a better quality build unit, but its size was perfect for our packed vehicle and stowed nicely in a Swissgear laptop bag i bought from Staples for this sort of thing two years ago.
Something like this:
Quite obviously this is not a wireless streaming unit, but incorporating that into such a package only adds to its possibilities for connections (one does not always need the streaming option at any given time).