Novamin is also available in Canada and it does work. With daily use, rough surfaces and even macro sized scratches on the enamel get smoothed over with a hard protective layer over time. I've only ever seen NovaMin on the Sensodyne Repair & Protect toothpaste product line, where the words "Powered by Novamin" are discreetly placed on the box. The same Repair & Protect product line is available in the US with the same packaging, only without the Novamin.

In Japan, they have the Apagard brand with nano-hydroxyapatite. Pretty much the same compound that makes up the natural enamel, but in particle sizes small enough to easily bond to the tooth surface. It is so effective that they don't even bother adding fluoride to it. You can order it on Amazon or eBay, but you won't find it in stores outside of Japan.

It makes me wonder why these advances have not made it to the US. Instead, we see lots of toothpaste products marketing themselves as Enamel Defense(TM) or whatever, when it's just the same old fluoride in fancy packaging. It's like they're trying to drown out the real innovation with false marketing, so consumers don't know what to trust anymore.

The Magic Mouse is physically capable of doing most of, if not all, the things you mentioned. It's just a matter of responding to the input from the driver side, which the default Apple driver does not. Perhaps there is some legal problem with patents that's holding it up?

But google for "BetterTouchTool". It's a freeware tool that lets you customize the mouse (and trackpad, if you have a laptop) to do all sorts of cool things. I have my mouse set up so that two-finger click is a middleclick, and three-finger click toggles exposé. There's also stuff like multi-finger swipes, and tapping (as opposed to clicking). But not pinch or rotate yet.