I realized my 16GB iphone 4 says it has "9.64GB out of 23.8GB" memory left when I went to copy pictures off of it, does this mean its really a higher capacity but locked in for the OS? I wouldnt see why iOS would need 8GB of dedicated space anyways.
Heres a screenshot:

http://dl.dropbox.com/u/18562797/24GBiphone16GB.JPG