Tethering will enable iPhone users to connect their Mac or PC to the Internet using AT&T's data network instead of Wi-Fi. It's a useful feature for business travelers or others who need access away from a faster network. The feature during the introduction of iPhone OS 3.0 earlier this year.

But the absence of AT&T's logo from a keynote slide at Apple's Worldwide Developer Conference (WWDC) in San Francisco earlier this month, paired with , has left customers wondering when AT&T will enable tethering, and whether it'll cost extra.

Nature abhors a vacuum, as does the Mac Web. Rumors are afoot that AT&T plans to sock customers with a heavy surcharge if they want to use tethering. It's the latest turn of the worm as disgruntled iPhone users in the United States complain more and more vociferously about AT&T's exclusive distribution arrangement with Apple.

AT&T has hoping to put the rumors to rest, though it stopped short of saying when it will activate tethering or if there will be any added cost at all.

"There are a lot of reports out there, but wanted you guys to know that rumors of $55 tethering plan on top of an unlimited data plan are false. We'll have more news to share when the iPhone tethering option is closer to launch," reads a statement on the company's Facebook page.