I like my iphone but one thing I continually have trouble with is the keyboard. I have big thumbs and when I text, I am constantly correcting text message and emails because my thumbs do not work well with the standard keyboard. Another example of some difficult touch targets is some ‘submit’ buttons and name fields.
The article below points out some great facts about touch and screens. They give great points and tips on designing for touch, and how the visual target needs to be big and clear. I find a lot of ads, and some websites have a small “X” to close and I can never click the x on the first try. It is frustrating and can sometimes make me close the app completely or have a negative feeling to whatever the ad is for. Knowing about the centroid now, I will try and touch it thinking of the center of the thumb, but I still think it is a design fail, and the touch target is too small.