I have a Vikuiti DQC-160 screen protector laying around right beside my monitor. Of course I can't say anything about it - since the N900 itself isn't even shipped yet.

My decission for Vikuiti was based on quite some reasearch in several PDA and smartphone forums. Durasec only got very mixed comments, especially a sticky film when removing the protector appeared in some comments. Vikuiti protectors recieved basicly complete positive comments.

In addition to that, schutzfolien24.de offers free shipping for germany. So I only paid about 9,- €uros for the protector. Delivery was fast, ordered on sunday evening, it got shipped monday morning and I got it on tuesday.
Their international site would be protectionfilms24.com, just search for the N900.