When you buy a new iPhone from us, we'll give you 12 months of unlimited web and Wi-Fi. It's called the O2 Web & Wi-Fi Bolt On, and you'll be able to keep it at the end of the 12 months for £10 a month if you like. We'll let you know when it's time.
To get your 12 months, you'll need to use the new sim that comes with your iPhone 3G. If you're already on O2 Pay & Go, it's easy to transfer your number to your new phone. Just fill in this form.
Don't forget, if you're on Pay & Go, you won't be able to get Visual Voicemail, call merging or Internet tethering. And you'll need to change your data (APN) settings to use services like mobile internet.