A popular tethering hack that allows your computer to access the internet via your iPhone’s cell connection is broken with the iPhone 3.1 update. The update also disables MMS messaging enabled by the same hack.
The hack is enabled by changing iPhone’s AT&T carrier file. It’s easily enabled by visiting sites like BenM.at using mobile Safari on the iPhone, and appears under the Network settings. The option is removed under 3.1.
AT&T will roll out multimedia messaging for the iPhone on Sept. 25, but hasn’t given a release date for tethering, saying only it will be available “in the future.”