Can I use my old T-mobile blackberry pearl with Verizon now that I have changed networks?

I have heard about unlocking you phone to use on other networks. Can someone please direct me how to do this? I bought a blackberry pearl with t-mobile and then my work dictated that I have to use verizon. I want to use my old phone with my new carrier.Can I use my old T-mobile blackberry pearl with Verizon now that I have changed networks?
You can get a code to unlock the phone, called the T-Mobile Sim Unlock Request. This service costs upwards of $60. But the good news is T-Mobile gives you the unlock code for your Blackberry free so you may use it with a different provider.

There is a condition T-Mobile has to get the unlock code for the Blackberry Pearl, you have to be under the original contract for atleast 90 days/3 months before they can give you the unlock code free.Can I use my old T-mobile blackberry pearl with Verizon now that I have changed networks?
I believe you are out of luck there. T-Mobile is GSM and Verizon is CDMA and the 2 are not even remotely compatible
you cannot use any cellphone that has a sims card with verizon