Something I find particularly annoying when using Windows Mobile is the assumption in a lot of screen designs that the primary method of using it will be buttons and stylus. I personally think the best method to use a WinMo Pro device should be your finger. A prime example of a screen that should be changed is when you hit the Call/Green Phone button when in the SMS inbox or viewing an SMS. You get a screen which shows the number the selected SMS came from in a text box to edit. From this screen, you have a two commands, Call or Menu. hitting call obviously calls, but the problem is, if you didnt mean to bring this up, its a pain to back out of. I would have assumed pressing the hang up button would get rid of it, but it doesnt. The screen is modal over the SMS inbox and you have to open the menu and select cancel to get rid of it. For a touch screen OS, why is there not a big thumb size call button, and a big thumb size cancel button. And on any OS, why does the hang up button not cancel an operation started by the call button. Please look through the UI for these kind of screens and sort them out MS.
