1.) First install the WP Dev Tools and unlock your Samsung phone.
2.) Use the Application Deployment tool to send THIS to your phone. You do not need to run it and you can delete it after it has been deployed.
3.) Install the Diagnosis app by typing ##634#
4.) After the Diagnosis app starts type *#9908# and select 'System Tweaks' press 'Save' then 'Close' and restart your phone.
and then a drop-down "Select GPRS"
-> Gumi Test Bed
-> Suwon2g Test Bed
-> Suwon3g Test Bed
(I don't see option to select "System Tweaks")
5.) Your phone now has internet sharing and as a bonus is interop unlocked!