I have a Samsung LN40D503 and it has a USB port on the back. According to the manual, you can play music and look at photos but that's all. I have videos on a portable hard drive that I'd like to watch on my TV as well as my PC. Is that possible? The only other USB port I have is on my DirecTV HD receiver (HR21-200) which, according to my internet research, doesn't do much. I've been searching for the answer to this and can't really find anything concrete so any and all help is much appreciated!
"According to the manual, you can play music and look at photos but that's all". Your manual answered your question. Music and photos -- not video. You could contact DirecTV regarding their usb port, but I would not expect much there.
You can always burn the videos to a DVD then play them on a DVD player through your TV.It worked for me.