I think you are covered by his second paragraph if you work with such strong acids.....

My N800 looks and works better without a screen protector. In three years I have not scratched it. I never lay in on it's face or put in in a pocket that has coins or car keys. Most people are not as careful. They need a screen protector.

I've had a Zagg invisible shield on my N900 since I bought it. If you install it correctly, there are no bubbles and the protection it offers is astounding. It's been on my phone for a year now with no peeling or signs of fatigue.

I've demonstrated it to friends before by taking my keys and slashing at the screen a few times, or a beer cap...

In fact, the LCD broke one drunken night and there was no damage to the external display at all, so I was able to just replace the LCD.

I would recommend BestSkinsEver.com because they're cheaper, but they don't have a N900 cutout available -- however they use the same material that Zagg does to make their protectors.

I used a JAVOscreen protector on my last 2 PDAs, my N900's had it since day one, no problems.

The N900 doesn't have the toughest screen, here is a link to a scratch stress test on the N900 which might help you decide on whether you need one or not. Personally I'm not as careful with my things as perhaps I should be, and I know if I didn't use a screen protector I'd regret it. There was one occasion where I pulled it out of my pocket and discovered the screen protector was scratched to the point of almost being unusable, I can only think that I must have put my keys in the same pocket briefly, but I don't remember doing it and even if the actual screen is tougher than the protector I can't imagine it would have remained unscathed without the protector.

I've bought some cheap ones off ebay, and they've been good. But for applying them I always seem to have trouble getting them on without at least one piece of dust getting in the way, but the ones I've bought are washable, so if that happens I can give it a quick wash and try again and having a little bit of water left on it from the wash doesn't hurt and quite possibly makes it easier.

Since month 1, I had a screen protector on my N900, so I cannot say what it would look like without one. But the screen protectors (cheap one from ebay, 5 for $1.50 including shipping!) accumulate scratches of their own regularly. In my mind I tell myself "that scratch could have been on the screen! Glad I have the protector!" but in reality, who knows...

I mainly use fingernail or stylus to touch the screen. Fingernail can especially be sharp and I've "sliced" through the screen protector with a freshly-trimmed fingernail more than once. I try to be careful on the days when I trim. Yeah, I could file them but that's too girly...

I only use the sticky screen protectors, not the kind you apply with liquid. My technique to prepare the phone:

Turn on the hot shower. Not so hot that mirror is foggy, but hot enough to get lots of moisture in the air. This will keep dust particles away and help avoid static electricity. Take phone into the bathroom, put some clean surface on top of the sink to work on it.

I use a microfiber cloth (terrycloth type, not the smooth silky kind) to clean the screen surface. The microfiber plus the slight moisture in the air will help to wipe i easier, no need to wash it with any liquid. You must ensure there is not a single spec of dust or hair on the screen or else your screen protector will not go on smoothly.

Second hardest part is to apply the sticky screen protector and get it aligned. You really only get 1 chance to apply it, once you peel it, dust will be all over it and it's ruined. (Ignore the ones that claim to be washable and reusable. Good luck trying to do that...)

If you peel the backing all at once, it's difficult to hold without ruining it with a fingerprint or getting dust on it. My method to apply it straight is to only peel about 2cm of the protector backing, not the whole thing. Start with only that edge, get it lined up straight, stick and hold it with my finger, then slowly peel the backing as you apply the rest of the protector.

If you get air bubbles, those are not a big deal, you can smooth them with your finger or with the stylus, gently push on the non-bubble part and work the bubble toward the edge of the screen, eventually you'll get it out. Even if you don't "force" them out, they usually go away on their own in a short time.

Dust "bubbles" are the real problem, they won't go away. If you have a piece of dust or hair, forget it, that protector is ruined. Peel it off and try to clean the screen again and apply a new one.

That's where buying cheap ones is handy, no sadness when you have to scrap it because of dust or because you applied it crooked.

I've only tried a couple of screen protectors so far (I've only had my n900 for about a month); I had a miserable time trying to apply them without embedding bits of dust beneath them or misaligning them to the screen, but I've had one on for a few weeks now without any perceptible reduction in brightness or sensitivity. This one is a "Lexerd TrueVue"; one thing this brand provides is a couple of fingers from a plastic glove, allowing you to touch the sticky side of the protector without getting it dirty. This made it much easier to realign the protector!

I dont know whether a screen protector is absolutely necessary, but I do enjoy using the stylus; and the combination of "long pointy instrument" pressed against "flexible plastic surface" just makes me nervous. Maybe it is completely unnecessary, but it makes me feel a little better...

Im surprised the Boxwave screen protectors are not mentioned here. I have had the cleartouch anti glare on my n900 for about a year now. It definitely helps a lot in the sun and of course no scratches.

Had the N900 "naked' for the first 5 mos, no scratches. I decided to go with Zagg's Shield just to be safe. Installation was *****, thanks to my impatience, and coupled with a 'sticky" feel, the Zagg was off after a couple of months.

Opted then for ClearVue, yet again managed to do a sub-par installation, though I liked the hard plastic feel and the resulting improved touchscreen responsiveness over Zagg's.

Added OtterBox, but found it too bulky, too heavy, and the keyboard case had a minor flex on one of the corners which started bothering me after the first 15 mins of use. But, I'll keep it around just in case I decide to pick up rock climbing or free skiing. I mean, the thing is f**king tank.

Went nekkid again for a month or two, but finally caved in again for Zagg. This time had it "professionally" installed (i.e. a 16-yr old in a mall charging me $5...) and so far so good. I think I can live with the sticky feel.

All in all, when it comes protecting your handset, I think it's 50-50 between actual protection and placebo effect.

Have you actually tried washing one? I initially thought the same, so I chucked my first screen protector without trying, but then I thought, what have I got to lose, when the next one got some dust on it, I tried giving it a soapy wash, a rinse to remove the soap, shook off the excess water and it applied just fine. And they were the cheap ones as well.

Also I tried running a hot shower and doing it in the bathroom like you suggest, it didn't help the problem with stray dust particles for me.