Typing on an iPhone or iPod Touch isn't difficult and is really a non-issue. If anything typing on Apple's iPhone is easier than most thumb keyboards! All it takes is a bit of practice and use to be able to type really fast but you'll find that it's possible within only a few days. Typing Tutor will help you in testing your skills and tracking the progress.
Don't try to keep your eyes on the letter you are typing. If you do, you'd try to put a sliver of your finger on the lower edge of the key you are going for. That will result in errors.
