I have a Verizon LG VX8300 and I'm trying to see if there's a way I can unlock this phone to use with my current T-Mobile service? I really need to know if it's possible or should I just give up hope?
Give it up. They use two very different and totally incompatable technologies. VZW uses CDMA (with no SIM cards) while T-Mobile and Cingular use GSM (with SIM cards.)
It is, unfortunately, not possible; as Kenstee said, the technologies are completely incompatible, like Macintosh and Windows.