iPhone's have a great UI, good game support, great web browser.
They are way too expensive however!! Locked to O2 if you want to do things by the book for the next couple of years at least.
When the battery gives out on your expensive investment, then what do you do?
A Nokia 5800 is a better phone because it's costs far less, takes Micro SD cards, has an FM radio, has a replaceable battery, is available for any network, has a higher res. screen, can forward texts, can cut and paste, works with BBC iplayer, streams live bbc tv, works with youtube, works with Nokia's free Sportstracker and other GPS apps such as Viewranger. Takes any 3.5mm headphone/earphone and has fantastic audio. The only limitation i can see is the limited number of IP radio stations in the realplayer format. The web browser is adequate, but not outstanding.
Nokia are a the biggest manufacturer of mobile phones, they dominate the market because they make solid, reliable products that work. The 5800 is their first touchscreen handset. A total winner!
Or be a fashion victim, have your wallet emptied and buy the limited iPhone!