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There are several tougher variations on glass. Borosilicate glass (once called "Pyrex", but the name has been sold and "Pyrex" today is not necessarily borosilicate) is tough and very tolerant of temperature stresses. There are various laminates of plastics and glass. A common combination is a thin layer of glass, for scratch resistance, on top of polycarbonate. That won't shatter; it dents or punctures if hit hard enough.

Cell phones should be using sapphire coated glass. Then you can put the thing in your pocket without a cover and not worry about it being scratched. The scanner glass at supermarkets is often sapphire coated, so it can handle years of canned goods being dragged across the scanner. Versace has shipped a "luxury cell phone" with this feature.

There's also a diamond-coated glass for that application. Diamond coating is much cheaper than sapphire, but not quite as scratch-resistant.

That kind of toughness makes real sense in expensive mobile devices. I was surprised that the iPhone didn't come with a sapphire or diamond screen.

This isn't exotic technology today. The typical supermarket checkout scanner uses sapphire or diamond coating on the glass. That's why it can survive years of canned goods (and, for Home Depot, hand tools) being scraped across the scanner. In the checkout scanner world, plain glass lasts 2-4 weeks. For diamond, the makers claim 9 years. The sapphire vendor offers a lifetime warranty.

They're not the only company doing this. Diamonex http://www.diamonex.com/ a subsidiary of Morgan Advanced Ceramics has been making diamond on silicon for years. I should know as I have a part of a wafer sitting on my desk at home. As for the people worried about heat dissipation, these things move heat amazingly well (better than copper). I've taken the wafer and on edge it will cut through an ice cube like a knife through warm butter. Unfortunately it will turn your fingers numb in about 3 seconds too from the heat transfer.

The cool thing would be to use sapphire or diamond on the screen surface. Not only would it be great for bragging rights, it isn't that expensive. Supermarket scanner glasses are often coated with sapphire or diamond; otherwise they have to be replaced every few months. Twelve hours a day of canned goods being dragged across the scanner glass is worse than anything that happens to a PDA-like device. Sapphire coated scanner glass even holds up at Home Depot.

The Nokia 8800 has a sapphire window.

Yeah, some of them are fake, but there's a huge supply of cheap diamonds out there. It's really hard to sell diamonds.

Industrial diamonds are appearing in more low-end products. Checkout scanner glasses. Low-end knife sharpening grindstones. Heat sinks. I'm surprised that the overpriced laptop didn't come with a diamond-coated screen.

Yeah, some of them are fake, but there's a huge supply of cheap diamonds out there. It's really hard to sell diamonds.

Industrial diamonds are appearing in more low-end products. Checkout scanner glasses. Low-end knife sharpening grindstones. Heat sinks. I'm surprised that the overpriced laptop didn't come with a diamond-coated screen.

Diamonex, of Allentown, PA, has been doing these diamond-like coatings for years. It's not a new technology, and Nokia isn't claiming it as such. The most common application is the glass cover on supermarket POS scanners. Diamonex offers a lifetime warranty on their scanner glass; it doesn't scratch even after a few million canned goods have been dragged across it. It's probably in a supermarket near you.

Diamond-like coatings haven't typically been used in consumer products because they were too expensive. The Nokia approach, a very thin coating on plastic, is probably the first consumer application.

To get the highest heat conductivity that you can from diamond films, you need to use isotopically purified carbon-12. Taking out that 1% of carbon-13 improves the conductivity by about 40%. Considering that normal diamond film has four times the thermal conductivity of copper, that's a lot!

Companies already exist to diamond coat objects up to 12" across and 1.5mm deep, so it can be more than "atoms thick" if you'd like. Here's a couple places that do it:
Diamonex.
P1.