It's been done before, and in many ways, but Cablevision's new plan for slinging what's on your PC to your TV might be one of the most interesting tries yet. Dubbed "PC to TV Media Relay," the new service will let subscribers that get their broadband internet and cable TV from Cablevision load up a bit of software on their Windows PC (a Mac version is forthcoming) that pushes whatever is on the computer through to a dedicated channel on the cable box. The real win here is the absolute lack of new hardware that's required (as far as we can tell), though we're guessing Cablevision is doing something fancy on the back end to route the video locally instead of streaming it over the entire internet. The service will start trials in June, and is a pretty overt move to keep users from dropping their cable TV service altogether as internet video continues to gain steam and Intel Wireless Display makes something like this into default functionality. In all, it's hard not to see this as just a stopgap, but it's certainly an intriguing one.