Cheap, Small LED or LCD Touch Sensitive Screens?

emf2268 asks: "I'm looking to either purchase or build (I'll do the circuitry myself if I have to) several dozen, small screens for an arcade game that uses a touch interface. Each screen, which should be around 6-10 inches, needn't be extremely advanced in the display department, since 16 colors will do just fine. An LED or LCD would do the job. But each screen also needs to be touch sensitive...it only needs to know if it's been touched, not where it was touched. How, can I build this as cheaply as possible?"