So just for fun, we graphed the screen sizes of some of the most common touchscreen phones. Shown on the graph are some current generation phones like the Touch HD and the iPhone 3G, plus some next generation devices (shown with a star) like the Touch Diamond2, T*Omnia, and Palm Pre. Not shown is the HTC Athena or Shift, since these devices are hybrid devices and not traditional smartphones.

It seems that the trend as of the last 18 months has been towards larger-screened devices. The Toshiba TG01 takes the crown with the largest screen, measuring in at 4.1″ (diagonal). I think that anything above 3.8″ (as found on the Touch HD and new Acer devices) may compromise pocketability.

What do you think is the ideal screen size?