Google "motorola V3 unlock code" and there are several options, all charging money as far as I can see though!
Some phone shops (not the network shops) offer unlocking, and you might haggle a decent price. I paid €20 last year to unlock a motorola in a place on Talbot St.
Check the terms & conditions of your agreement with the operator as unlocking the phone may be in breach of this agreement athough I don't know what penalties might realistically apply.
Be aware that some websites that purport to provide information or software for phone unlocking may be conduits for malware and viruses. Best to get specific recommendations from trusted sites/forums first.