I use these (
http://www.pocketpctechs.com/ ) with my Dell Axim x50v. No matter how clean ( or how new ) you keep your stylus you are bound to get scratches on your screen. Tapping isn't the issue here, it is the dragging of the stylus when writing, drawing, using scroll bars, etc. Using screen protectors is purely up to you, but I use them to protect my investment. It is also a good reselling point to say that you use them.
The ones in the link are pretty expensive ( $30-something for 2 ) but are considered the best and have a lifetime guarantee. The "clear" one that I use ACTUALLY improve screen contrast and make the screen look brighter while the "anti-glare" one DOES make the screen look fuzzier. The drawback to the clear one is that glare is pretty obvious while the the anti-glare one doesn't have a glare. I HAVE found that you have to press slightly harder on the stylus than normal and should take a day or two for you to adjust. You know you are ALREADY pressing too hard on your stylus IF your tapping, etc. is OK after applying the new protectors.
I wouldn't mess with the DIY solution or the Belkin ( or any other cheap ones ) as these WILL make your screen look like crap. I've been down that road already. :laugh: