Why'd you remove the mention of a PS3?
A
Slingbox is for the other direction you want... it takes what you would see on your TV (using e.g. cable/sat/Freeview STB as a source) & sends it over the internet for you to view on your PC/laptop.
Sling Media do make something called a "
SlingCatcher", which lets you use a PC or a Slingbox as a source, although without a Slingbox, I'd think you'd be better off just going for a straight forward networked media player of some sort.