The whole top of my screen was broken off, and after a while the cable controlling touch snapped. so after months of disuse i decided to fix it myself after going to a apple technical and them telling me it would be $200
It was difficult but after an hour i had fixed it, i could not be more happy.
make sure to repair any dented corners before placing the screen, or it will not fit in the housing
iPod touch (4th Gen) Screen
iPod touch (4th Gen) Adhesive Strips