Still remember NetShare, the application that allows tethering of the iPhone, which was removed by Apple? We knew Apple has a different plan about this and also wrote once that At&T is going to provide tethering plan to iPhone owners. Well, it is almost certain that tethering plan would be announced in the upcoming Macworld Expo 2009.

We have on many occasions discussed about the call quality and the patchy network coverage of AT&T. In view of this, the announcement is not likely to be part of the keynote address. Tethering plan for the iPhone could be made known as a press release during the Expo.

The tethering package is expected to be 5GB data cap at $30 a month. However, things are not that definite yet. The tethering plan compared to EV-DO or HSDPA card plan for mobile data, $30 is reasonable, but the tag is still steep when you think of jailbroken iPhone  users getting tethering feature for free. Of course it is not legal. AT&T can nail you anytime for draining data without paying.