If I am mistaken Im sure someone will correct me, but its my understanding that most of the touchscreens anymore are the capacitive touchscreens like the iphone and ipad. I dont know of any other touchscreen technology that is widely used right now for consumer electronics. The only downside I can think that they have is that they dont respond if you touch is with something electrically insulating. So wearing gloves can sometimes be a problem or if you like to use a stylus you need one that will work with capacitice screens.
I was at Futureshop the other day and as much as I hate Acer, they had a really nice Windows 7 tablet. The screen wasn't capacitive, but it was still super nice. 30GB SSD, 2GB RAM, I forget the processor speed, but it was like $600. I was tempted.