There is a perfect camera for concerts. One of my mine is a nifty little Casio EX-S500 that is about the size of a credit card. All sounds can be turned off, even when powering up. I can take pics all day without drawing any attention. Same with video, I can take over an hour's worth on my 1GB memory card. The quality of the video is pretty good, believe it or not. All these vids were taken with this Casio and have been compressed, and the quality is still good. The original files are crystal clear. Once you use the zoom with video though, the quality goes straight down the tubes, obviously. Front row video at a concert would be excellent.
http://www.iroc-zpostforum.com/Videos.htm
The quality of the pics are great as the colors are very, very accurate. Using a few tricks to get proper exposure, the quality is good enough to frame. I had one of my lighthouse pics printed at a graphic design and media studio to see if the quality would actually stand up, and it did.
They used to retail for over $400, but being they now have 6 & 7 megapixel versions, the 5 megapixel (EX S500) cameras can be purchased for under $200. Don't confuse the Z versions with the S models, the S models are a far better camera and the video is much better.