As long as your device is unlocked in some way (Developer/Chevron/Other) you can get internet sharing on your Samsung phone.
IMPORTANT: If you updated to 8107 via Zune you may have also updated your phones firmware. If this is the case you will not be able to use this hack. I would suggest rolling back to 7720/7740 and updating via CAB Sender using the cabs in Heathcliff74’s thread.
1.) First install the WP Dev Tools and unlock your Samsung phone.
2.) Use Microsoft’s Application Deployment Tool to send THIS (Update 8107 use THIS) to your phone. Don’t run it, delete after it has been deployed.
3.) Install the Diagnosis app by typing ##634# on the phone keypad.
4.) After the Diagnosis app starts type *#9908# and select ‘System Tweaks’ press ‘Save’ then ‘Close’ and RESTART your phone.
5.) Your phone now has internet sharing and as a bonus is interop unlocked!
6.) (optional) Press the ‘thanks‘ button at the bottom of this post if it worked for you.
PS: You need to have a recent mango firmware on your phone or your diagnosis app and drivers will not be new enough to work.EDIT: I built the file depoyer using the tools provided by Heathcliff74 so many thanks to him! Also, ADC is built in to this as well so no need to worry about that. I also upped the max number of connections from 3 to 5 devices.
NOTE: If you have internet sharing turned on (active hotspot) you will not be able to deploy XAP’s untill it is turned off. Also, as with any xap, you need to have your screen unlocked to deploy this to your phone.
SECOND NOTE: If you can’t get any XAP’s to deploy try turning ICS on then off again, it may correct some errors.
fix for the 8107 update, the following registry tweak needs to be made:
Set the “UserProcGroup” value from “32” to “5” will make IS work fine. Don’t forget to reboot your phone.
Anyone with data issues try:
Diagnosis > *#32489# > Back > Back (to Phone Control) >  Network Control >  GFC >  Setting Cancellation
Wait for it to say success, then reboot. This fixed all my data connection issues after applying this patch.
solution my wifi/cellular data 3G/4G conflict problem!
After numerous restart and changing different APN in Wireless Manager without any success, I went into WiFi settings panel and deleted my stored Wi-Fi networks. After rejoining, I got online instantly! Try it if all others fail!
Xap Download :