monetrun,
One of the inputs must be a tuner input through the co-ax for PiP functionality to work.
--HDTech
I just purchased this Samsung TV about a week ago. It has a great picture and the remote hasn't given me any trouble. I've watched a movie with my DVD player and played some Wii games. It was a great deal. Some reviews said the sound was bad. I disagree. The sound in behind the TV is a little annoying, but it's not bad. The real selling point was that it was one of the top TV's in consumer reports.
I had a little trouble setting up the channels at first because the screen that asks you to start scanning confused me as I wasn't sure what options to chose or what it was trying to do. So I went a day before I realized I had to scan channels to get the new digital channels.
I thought I was fairly good with technology, but the PIP baffles me. The PIP option is greyed out. I've read the owners manual and the forums, but I don't really understand the answers. The main frustration is that people are using terminology such as tuners but I don't see any answers detailing how to get PIP to work. I need a detailed explanation. How can I watch TV and see my Wii at the same time? Do I need new cables from the Wii and DVD player as opposed to the red yellow and white cables? Do I need an HDMI cable? I've tried watching TV over the air instead of through my cable company, but the PIP is still greyed out.
When I was a kid I used to be able to videotape myself playing videogames using two VCRs, but I cannot get PIP to work. Please help...
If anyone has found a way I'm all ears.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic