Recently i found some tricks and tools to unlock samsung Omnia i780 and i900. Thanks to _TB_TB_ on Xda developers for sharing the Unlocking tools and tricks for samsung Omnia. This Unlock tool works on i780 and Omnia. Here are the methods for unlocking Samsung Omnia :
1. At first download the Unlocking tool from this LinkFree Unlock Tools and tricks for samsung Omnia i780 and i900 (225)
2. Then extract the zip file and copy all three .lnk files to your Pocket pc.
3. Now browse the directory on your pocket pc and run Lock.lnk .
4. Now you have to find the MCC/MNC from this list wiki Link Mobile Network Code. Enter valid MCC/MNC of your carrier. He used his “real” SIMLock carrier ID 26001 for Poland, Plus.
5. As NCK, enter 12345678 . Tap OK and it should tell that SIMLock enabled.
6. Then run Status.lnk to see if its locked. And run Unlock.lnk
7. Now enter code entered in step 5 (12345678)
Now you unlocked your Omnia. So have fun with this little tool.