Of course. The iPhone glass screen is much more easily cracked than the N900 (assuming the N900's screen is not glass). However, even the iPhone's screen will get scratched. For example if you have a wedding ring with a diamond and reach into your pocket and the diamond rubs against the iPhone screen, you'll get a scratch. It is much harder to polish out a scratch on a glass surface than on a plastic surface.

If you look at the hardness scale :
http://en.wikipedia.org/wiki/Mohs_sc...neral_hardness

You'll see glass is roughly halfway. Sand contains silica and is used to manufacture glass and is well capable of scratching glass as well. There's a reason why sandpaper and sandblasting is used. If you look at number 9 on the scale: corundum, this is the material used as a synthetic sapphire crystal that is found in watches such as Omega, Rolex, Audemars Piguet, Blancpain, Patek Philippe, Panerai, Corum, DeWitt, IWC, Sinn, Doxa etc and any watchmaker that has a reputation for precision horological instruments. If you see the old Rolexes from the 60s or the Omega Moonwatch (that uses a hesalite plastic crystal as NASA were worried that synthetic sapphire could shatter, causing a problem in zero gravity) that had plastic crystals; they would scratch quite easily, but you can easily polish out the scratches using something like Polywatch.

Or try another alternative, see here:
http://www.timezone.com/article.aspx...=workbench0018