there are smaller cell phones, but looks like the size of this thing is "OK", particularly if it can do many things. the googlemaps is the "killer ap" on this thing meethinks, if it plays mp3 as well, thats gravy.
It's a phone that doubles as an iPod... or an iPod that doubles as a phone. Either way, you're getting full functionality of both.
A convergence device that's actually useful. Imagine that.