There are many ways to do this, but his TV isn't equipped for it. More modern TVs include something called "DLNA", or Digital Living Network Alliance. Many phones have DLNA built in too. So if he had a TV that supported it, he could play back videos from his phone on the TV. He'll need to get a device that he can connect to the TV that supports DLNA.
The Western Digital TV Live and Boxee Box are a couple devices that do this. Roku does not support DLNA, however. Apple has "AirPlay" in their AppleTV, but he'd have to have an iPhone to make use of it.
Leonard was wondering if there was a bluetooth option, but there isn't because it isn't fast enough. He could connect his Galaxy SII phone to the TV using an HDMI cable, though. Some phones have a special kind of USB port that can be turned into HDMI with the appropriate cable.