I've used "Invisible Shield" from Zagg on my Samsung Instinct and will get one for my Moment also. It will have bubbles for about 2-3 days, but then dries crystal-clear. I have scratched it real hard with a key like they do in the vids and it surprises everyone how scratch-resistant it is.
The only downside is that it is pricey.
Click on the link at the top of the screen called "Scratch-Proof your Samsung Moment" to see the vids, though I don't know if this site has a coupon code.
I have just gotten invisible shield for my moment. It is true protection is second to none. However there is the HUGE drawback that screen sensitivity went down a large amount. The screen is FAR less responsive and I simply hate it!