With all the Internet-savvy phones like iPhone could easily strain other carriers' networks in the near future. By 2010, global mobile data traffic is expected to exceed 200 terabytes per month, six times last year's levels, according to Cisco Systems.

Why? One reason is more phonemakers are catching on to the trend of touchscreen that made the iPhone a hit. As you can see, more people are carries high-end multimedia smartphone like Samsung Omnia, Blackberry Storm and etc...

Users of phones with Google's Android operating system spend roughly as much time online as iPhone users, according to mobile advertising company AdMob in USA.

Some carriers may try to offload data traffic due to network bandwidth congestion. PCCW, the Hong Kong operator, has started using Wi-Fi hot spots to ease the load from smartphones and its digital TV service.