Myself and many others are using these: [URL="https://www.apple.com/search/Power-Support-Anti-Glare-Film-Set-for-iPhone-3G#mn_p]
Power Support Anti-Glare Film Set for iPhone 3G[/URL]. I am really happy with them. The really nice thing is that they do not show fingerprints, etc. Also, if put on right, they work nicely with slider cases. A lot of the other brands end up getting pulled up around the edges when you put the case on it.