I went 2 years ago with a group from the school where I work. We had a lot of fun, but the whole process takes forever. You sit around and can't leave from about 8 til 11. Then they call the audience around the corner in small groups and quickly screen you. You have about 20 seconds to make a big enough impression for them to select you. (It's not random as the show would have you believe.) Then you wait some more...and then you go inside, where the set is surprisingly small. One of our teachers was selected and she won a few prizes, but nothing big, like a juicer and a shop vac or something. If you are in the audience you have to be obnoxious and loud the whole time. I was so tired when it was over, just from the smiling! Bob Barker was nice. It was funny to watch him snap back into show-mode when the breaks were over.
My cousin was on it last year. He had just graduated from the Air Force Academy and went in uniform with some of his buddies. He got picked! He won a jacuzzi and an electric guitar, I think. He's adorable, so we were not surprised he was selected.