iPhone 3G, 3GS and 4 come with 12 month warranty and 90 day complimentary technical support.

AppleCare Protection Plan for iPhone:

• Extends the complimentary Technical Support from 90 days to 2 years
• Extends the manufacturer's warranty from 12 months to 2 years

2G iPhones are entitled to up to 2 years of complimentary Technical Support while connected to O2.