HDTV computer connection

I've notice that the new HD televisions have a computer port for VGA and sound, if you connect your computer to them you can stream from your computer to the television and watch you computer on the TV. How about from the TV to the computer? Is there a way to capture videos from your tv to your computer with this connection? If not, what can you use, I've noticed the new HD units only play and don't record. The HD units I've seen do not have a video output, only audio. What can I do to capture onto my computer?:confused