Size really does matter in the mobile experience as there is a balance between portability of the unit and the usability of the device. Make a large device and it’d be easier to use as input and reading information from the screen would be a good experience, but you’d sacrifice the mobility aspect of the device. According to Engadget Mobile, if you’re curious how the new crop of devices stack up, Apple’s iPhone is the largest with the Touch Pro the smallest (depth not included in comparison) based on the front surface area.

The HTC Dream, HTC’s first device running the Google Android operating system, fits somewhere in the middle being slightly smaller than the iPhone but larger than the upcoming XPERIA X1 from Sony Ericsson and the Touch Pro.