Chris Rydberg carries on his examination of the gaming market with the US launch of the Playstation Portable. In part two, he sizes up the three big players (and find out it's really two big players and the N-Gage, but there you go). "There We Were, Now Here We Are: More on the Second Handheld Gaming War" is here.
We're In The Second Gaming War - Who's Going to Win?
You overrated the N-Gage and underrated the PSP.
To use GPRS you must have a GSM plan. In the US and South Korea that's not a given. GPRS has limited bandwidth.
The PSP has ad-hoc Wifi. You can play direct multiplayer handheld to handheld.