So your phone is currently on sprint?
What are you wanting to flash it too.....?
Mine was on Sprint but I did manage to fully flash it over to CricKet. I am using the Cricket $55 android/smartphone plan.
Had a hell of a time convincing them to put me to the android plan once they realized my phone was flashed. Typical CricKet.
I used software to flash mine, then did the custom rom/kernal bit awhile after.
I cannot remember what the software was called, but I am trying to find it now. (It covered ALOT of providers)
THIS was what I used to put a custom recovery on my LG Opt/S (I only used RecoveryFlasher, Could not figure out ROMtools) ---->
RecoveryFlasher/ROMtools
The ROM I used ---->
Unofficial CM7 for LG Opt/S