iPhone 4S vs iPhone 4 vs 3GS

Old and new compared - which should you buy?

iPhone 4S

The iPhone 4S is here - read our iPhone 4S review - so we've taken an in-depth look at the key specs and seen how it compares to its year-older sibling, the iPhone 4 and two-year old iPhone 3GS (read our iPhone 3GS review

) – still going and now the budget handset of the pack.