If a surface or substance is sharper than something else it will scratch it. When they try to scratch these screens with keys say and moderate pressure it tends to remain unscratched which is pretty impressive. Of course it can be scratched. n900 has an awful scratch resistance.
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...