IFA: Mini Key keyboard from Nuu converts iPhone into a flipping clamshell – Mobile Magazine
I personally haven’t had problems typing on the iPhone, but I can see how some people prefer tactile keyboards, especially if they’re adept at typing on mobile keyboards without looking. This prototype looks like it has the 3Gs or 3G in it, but the description says it’ll be available for the iPhone 4 as well.
Check out the article for more details. :)