I could unlock iPhone 3G with yellowsn0w tool
First i had thought that its impossible for me, but finally i unlocked my friend Varun’s iPhone 3G which he got from his brother who lives in U.K. So it was o2 network with which the phone was purchased and we wanted to unlock it for our Indian networks.
Since there was no other choice than trying it out, i started the process with how CrunchGear and the iPhone Dev Team explained, and stuck in middle for couple of times. There i used my own brain and luck to tweak a few things in the iPhone network and Airplane settings, which did work and the iPhone got unlocked in around hour and half.
Here is a guide on how to unlock iPhone 3G and also posted the same story of how i successfully unlocked iPhone 3G.
You would enjoy reading it, and i suggest you to try the guide if you want to unlock the iPhone. Works great and doesn’t damage anything if at all it does not unlock.
Here is my friend calling me on the iPhone with Airtel SIM installed in it -
The yellowsn0w tool was awesome one and really did work! Many people reported that it doesn’t work. But it at least did on my side 
Posted in Amazing on January 4, 2009
January 5th, 2009 at 4:16 am
Awesome dude…Good you blogged it.It worked.
January 16th, 2009 at 10:25 am
Dude,i have on Apple iPhone,which i brought from US ,but im unable to unlock it..
Can you unlock it,if i come to Hyderabad and get it to you ??
Let me know please..
June 13th, 2009 at 8:10 pm
Yelowsnow would definately work on iphone 3g phones EXCEPT for those iphone 3gs which have the Modem firmware 2.30 ….. settings->general-> info ….. there u see the modem firmware. So if it is less that 2.30….. Ur phone will get unlocked FOR sure!