Upgrade iPhone 3G 8GB to iPhone 3G 16GB
I am a current user of a black iPhone 3G (8GB), and I've decided I would like to upgrade to an iPhone 3G (White, 16GB). I was wondering if anyone has experience doing this, or if it is allowed by Apple. I bought my iPhone 3G the day it was released in mid-July, but was wondering if it is a simple (or possible) process to go to the Apple Store, purchase the white iPhone 3G for $299, and then sell my current black iPhone 3G. Any advice would be greatly appreciated. Thank you!
Macbook, 2.2GHz Intel Core Duo, 4 GB Ram, Mac OS X (10.5.5)