Thanks to XDA-Developer member OndraSterthere is now a hack available to enable internet sharing on Samsung Omnia 7â€™s running Mango.
Interestingly the hack confirms Microsoftâ€™s assertion about drivers, as the hack does not work on HTC handsets. The hack also reveals that there is vestigial support for Bluetooth tethering, but that this does not work.
The hack also disables the phone from checking for carrier provisioning for tethering, but this of course does not mean you will still not be charged.
The hack is a bit too complex to explain here, involving unlocking the handset, provisioning the device, replacing files and editing the registry, so really only for expert users.
Head over to XDA- Developers for full instructions.
Thanks RyoTGZ for the tip.