[tonycommander]

what i want to do is this....

have a single 'device' that plugs into a 'cradle' which then plugs into an amp - in one of many rooms... (therefore needing multiple cradles...)..

Again, prf HD storage, not solid state - wanna put my entire CD collection on it..

(Dont have a wireless n/work at home yet)

Pref. playing either MP3 or WMA, does such a beast exist that I can move around the house?

[JohnG]

I sit my iPod in the docking station and plug it in to whichever hifi I want to, I just move it to the room that I want to listen to it in.
If you do then get a wireless network you can use the Apple Airport with iTunes to wirelessly transmit the music from the PC to multiple hifi amps.

Not what you're looking for but Samsung have started including USB ports in to some of their gear which is kinda funky... Supports MP3 players of all forms as well as cameras.