With the advent of streaming and on demand services (Netflix Instant, Rhapsody, etc.), I got an idea.  
 
I want to know if such a device exists.  And if it did, it would probably would fall into this category.  Basically I want a device that has mobile broadband with digital outputs.  I think it would be nice to have this amount of portability.  I could take it to a friends house and listen to music, watch movies, etc, on a TV or stereo.
 
I know I can do this with a laptop, but a hand held device would obviously be more convenient.
 
Thanks.