I just replaced my touch screen glass (aka digitizer) today, and I'm pretty happy about it. Previously, the left half of my screen didn't accept clicks. The screen came from ebay seller hi-etech and instructions were on ifixit.com. Just make sure you ask them for a T3 torx screwdriver or you won't be able to get the display module apart.
By far the hardest part was getting the touchscreen connector back together. Those little ribbon sockets are a pain.