Samsung Galaxy S2 black for swap .

I have a 4 month old Samsung Galaxy S2 on 3 mobile. Immaculate condition, boxed with all accessories. Not looking to sell however I am looking to see if someone would swap for a white Samsung Galaxy S2 OR a white iPhone 4 (or 4S) in similar condition. Would prefer that it was unlocked so I can see the phone work on my network etc.