There are several screen protectors that are either available or will be available shortly (for the n900). There are other threads that list many of them and whether people liked them or not but not any good "reviews" or comparisons between them...so it leaves you having to connect the dots and many times there are gaps between the information.

What I am looking for is responses from people who have used protectors (especially multiple ones) and give their reasoning why they liked them and/or why they chose them over other products. So basically more than "I use X and like it".

Let me say that I don't have an N900 and I don't use a screen protector on my N810 but I have used a variety of protectors on my various Palms. Based on my experience, let me lay out what options you should be considering.

The first thing you have to decide is whether glare is a problem for you. Screen protectors can be clear or glare resistant. The latter have a rough surface which disperses some of the incoming sunlight to reduce glare. Unfortunately they also disburse some of the outgoing screen display light so your screen will seem dimmer. I, personally, like the glare resistant version but that is due to another characteristic (they have a better feel when writing on the screen with a stylus) that will probably not be a big consideration with the N900.

Screen protectors also come in lighter and heavier weights. For PDAs, heavier weight protectors are easier to install and last longer. Boxwave was my brand of choice in a heavy weight protector. However, I suspect that a heavy weight protector may affect the touch sensitivity of the N900. If this is the case, a lightweight protector, such as the Fellowes, might be a better (and cheaper) choice.

There are also screen protectors which claim to be removable, washable, and reusable. I have not had good experiences with any of these. I would recommend leaving the protector on, cleaning it with a microfiber cloth, and replacing it when it becomes noticeably scratched.

If it were me and I was dealing with a $600 device, I'd buy a pack of light protectors and a heavy protector and try them both.

What's the very top layer of the N900's screen? Is it something that might become degraded with frequent removal of the more sticky kind of screen protector?

I used the InvisibleShield on the n800.

Pros

- It will protect your device, it doesn't get scratched or damaged easily
- Somewhat easy to apply with the materials and directions they provide you
- It lasts a long time

Cons

- The fact that it was developed for the military as they advertise shows.. the thing is thick and reduces touchscreen sensitivity. It's hard to draw with the stylus

- It gets dirty easily and is slightly difficult to clean
- Feels rubbery when you touch it


I am currently looking at Durasec screen protectors (if anyone has any information about them like reduction in touch screen sensitivity or rubbery feel that would be appreciated). I'm going buy a hard shell for the n900 and a screen protector.

By invisibile shield, you mean zagg?

Yes, Zagg's InvisibleShield. Their skins are probably very good for protecting the device but the actual touch screen makes you go meh if your using a resisitve touch screen.

I guess I'll get their full cover, then purchase a different screen protector. I do plan on leaving my N900 in my pocket, so I don't want to scratch up the phone.
By any chance, do you know if ZAGG's protector cover up the side of the device?
Forgot to ask this, how exactly does the ZAGG stick to the device? Do they use adhesive or something?

Their fullscreen cover consists of both the back and front, so you'll be paying for the front and not using it (though you could resell it I guess).

No clue if they cover up the side, I've only bought their screen protectors. My judgements on how they protect the body is based off what I know about the screen protector since it's the same material.