It's probably just like the available free software out there that does the same stuff.
You put a program on your PC, that programs shares whatever you want, such as all your music, videos, etc; and then you can access your files with a username and password from anywhere with internet.
Streaming videos tends to suck if they're high quality, but music usually works fine, as well as pics or text. I tried www.orb.com and that worked fairly well...we used it on my Wii at a friend's house to look at some pics from my PC.
LEFT4DEAD411.COM
Bet with disolitude: Left4Dead will have a higher Metacritic rating than Project Origin, 3 months after the second game's release. (hasn't been 3 months but it looks like I won :-p )