Cellco Partnership dba Verizon Wireless via Page Plus
Nextel IDEN via Boost
^^ I think the Sprint TP2s came unlocked for SIMs outside of the USA. Meaning, you could take it to Europe and it would work right away. To use it for a USA GSM operator, you need to get it unlocked. Check PPC Geeks forum. I don't know of a free method at this time.
Possibilities to unlock...
You can unlock your mobile by getting unlock codes from the website mobileunlocksolutions.com for reliable cost.Give the required details in the website and get the unlock code.