Late Tuesday Apple made the fourth beta of iPhone OS 4.0 available to developers. The newest software for the iPhone includes mostly minor tweaks here and there, but there's one huge surprise: tethering.Apple kept to its every-other-week schedule for delivering new builds of iPhone OS 4.0 to developers. After downloading and installing the new system software, developers and tinkerers started digging in to see what is new.

One of the first things noticed by Gizmodo was a new screen that would let users set up tethering on their iPhone. Under the network settings, there's a tab for "Set Up Internet Tethering." When users click on that, they are greeted with a pop-up message that reads, "To enable tethering on this account, Contact AT&T at 611 or visit http://www.att.com/mywireless." Below the message are buttons that would initiate a call, or take you to that web site.

A few things to keep in mind. Just because the option is there in no way implies that tethering will be included in the final build of OS 4.0 (in the U.S., anyway). The iPhone has been capable of tethering since last year, only AT&T has not enabled the service yet in the U.S. The appearance of this option certainly gives hope to those who want use their iPhones to tether, but it is not a guarantee that AT&T will offer the service any time soon.

Just a few weeks ago, AT&T told tech blog Engadget:

That language says pretty clearly that AT&T isn't ready to offer the feature. Will it be ready once iPhone OS 4.0 goes live to Joe Consumer later this summer? We can only hope.