I wrote about Orb a while back - some friends of mine were working there and showed me some cool demos. With Orb you can access your "stuff" - pictures, music, recorded TV, even live TV streams, from any device with a browser and media player (PCs, phones, Macs, etc.).
When they launched they were going to charge $10 a month. I never got a bill, assuming it was because I was so special. In fact, they never invoiced anyone and now the service is free. Orb will get paid by serving up ads on the Orb site, and maybe even within the content. You need a PC for Orb, unlike Slingbox, but hey it's free!
I installed Orb on my Media Center PC and it is quite slick, although the web based navigation is still a bit cumbersome (and the UI looks like it was designed by engineers). One great scenario is that I can whip out my IBM X41 and view a recorded show anywhere in the house (or on the road). My kids can even catch up on some Fairly Odd Parents on the Mac G4 upstairs.
The quality is quite reasonable over 11b WiFi (10Mbps). I've used my Windows Mobile phone to watch shows using WiFi but i suspect that GPRS would be too slow. The music functions for listening remotely are cumbersome - I'd like something that integrates better with the library features of Windows Media Player, but hey - it's free!