O2 has disclosed its new tariff plans for smartphones, together with Apple's iPhone 4 that was revealed by Steve Jobs this week at the corporation's Worldwide Developers Conference (WWDC).

The fresh tariff plans that are offered as either 18- or 24-month agreements, are charged from £25 and go together with call packs of between 100 and infinite minutes, in addition to unlimited messaging.

However, the network has also decided to limit its previously 'unlimited' data offer.

Consumers giving between £25 and £35 a month on a 24-month bond or between £30 and £40 a month on an 18-month deal are entitled to a data grant of 500MB a month.

On the other hand, those whose tariffs provide 900 or 1200 minutes every month will learn that their data is restricted at 750MB, whilst those on the infinite monthly contract get a 1GB data usage.

Thomas Wehmeier, Principal Analyst at Informa Telecoms and Media, said, "O2 had become the industry poster-child of the capacity crunch era".

He said that there's a lot of discussion regarding the appetite for data of iPhone consumers, but their study reveals that the most of the users will be content with the 500MB of data that will be served every month.