I took out my LG DM150 phone to make a call yesterday and it prompted me for a four-digit unlock code. So I looked it up in the manual and it said to enter 0000 … didn’t work. 
So I turned to Google and guess what, my friend Henry had a page on unlocking the same phone. It’s very simple really… just enter the last four digits of your phone number. Though I live in Ghana and use the kasapa mobile network, its appears it doesn’t matter what your carrier is or what country you live in. In my case, I had to enter 8690 since my cell phone number is 028 731 8690.
All the other methods (enter 0000, 1111 or 1234) did not work for me so I really recommend the enter-the-last-four-digits-of-your-phone-number method. 
Yes! that method works
enter last 4 digit of your mobile phone number
tested on LG BSNL india
regards
sam
By: Gaurav on November 28, 2008
at 12:06 pm
good
By: clement bening on February 6, 2009
at 9:41 pm
you can unlock your phone on the website http://www.unlock-phone-lg.com.
i unlocked mine xenon there
By: lg on August 10, 2009
at 8:54 am
Last four digit of the phone no also worked for me..
Thanks
By: Tushar on July 20, 2012
at 8:04 pm