SBSettings is a great application to quickly turn on and off different services. Recently two developers have released tethering toggles to easily enable and disable iPhone tethering from SBSettings.

The first called, "Tethering" by Filipe Pina makes changes to the files that the preferences framework makes, then restarts the service. The second called, "Tether" by Ryan Petrich uses the preferences frameworks and calls the functions that the settings app calls.

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According to BigBoss, both toggles work well. You can download togles and SBSettings via Cydia (for jailbreaked iPhones only).

via iclarified and bigboss