Within the first few days I may have said you have a slim chance.
Two months later I may have said you're stuck with a 16gb phone because you paid for an iPhone and it's contract, which sticks you with it for two years unless you want to pay a cancellation fee and any return fees.
May I also add that "Mint Condition" would be unopened, untouched, and still in it's original state in shrinkwrap and all. I assume that isn't true as you can't walk out of a distributor (or at least aren't supposed to) without having it opened and activated, and the fact that you sound as though you've used it and discovered you don't need all that space.
If it's used, you're stuck with that one. As far as I know, and believe me I've tried, you can't swap between models or downgrade to the first iPhone. I've tried for a 16gb of the original, upping my 8gb. You can only upgrade.
The next iPhone should come June-ish like the first two. Perhaps you can get a break on upgrading to the next one should you want to.
I may have also said you could give it to me if you really want.
May have.