Apple Inc. (NASDAQ:AAPL) released iPhone OS 4.0 Beta 4. Beta 4 has a new feature built in: tethering. Under the Network feature in the Settings menu, there is a button that says Set Up Internet Tethering. The biggest problem with Internet Tethering through AT&T is that it doesn’t come cheap. If I remember correctly, AT&T was planning to charge $30 per month for the service. [Gizmodo]