The top layer on a Sony Touch is not glass. That's the flexible plastic touch layer. I use Stoner's Invisible Glass on a microfiber rag, but not the kind used for cleaning glasses. An example can be seen
here. Stoner's is available at Wal-Mart and Lowe's. It has no dye or soap, so no streaking, and it's not harsh at all. Matter of fact, it's reccomended for tinted windows. Use it once, and you'll be using it on all of your various screens, windows, mirrors, etc...