I was happily droiding it up on my phone today, typing a twitter update on my phone earlier. I must have swiped my finger across the screen by accident because a little number/symbol slide came out of the stock Android keyboard.
I am running FroYo, so I have no idea is this is limited to 2.2 phones, but I couldn't stop grinning. Thats the kind of thing that makes Android an excellent platform. Check it out for yourselves, if it is in FroYo only, its a damn good reason to upgrade now.