O2 has announced that starting April 3 it will introduce a new 24-month tariff option for iPhone customers that will see a “free” iPhone 3G bundled with a lower minimum tariff than before. Customers signing up for the 24-month £34.26 tariff plan, which includes 600 minutes, 500 texts, and unlimited data and Wi-Fi hotspot service, will receive the 8GB model for free, while the 16GB model will be priced at £57.74. Customers will be able…