I have a couple HDTV calibration DVDs, and I actually used one once. Now that I've replaced the bulb on my Sony WEGA TV, I probably should do it again. But I just found out about an interesting location for a calibration tester in this NY Times article:
If you own any Sony Blu-ray discs then you have already have the calibration tests you need. Type in "7669" in your DVD remote control and press enter – the Sony Blu-ray will lead you through a series of tests and screens to get your monitor perfect.
No you should not choose Blu-ray
Cool -- we have a Sony Blu-Ray-- I'm going to have to try that.
I never realized the thing needed to be calibrated although it does seem kind of obvious now that I think about it. I'll have to look into it.
Most TVs, including HDTVs, are set in the factory to be very bright, just in case they are set up in a display room. It made a pretty noticeable difference when I calibrated it once.