BlackBerry FAQ: Can I use a Verizon BlackBerry Storm on Sprint?
I seem to get that question a lot, here is the closest thing I can get for you as an official answer. According to Sprint customer service, yes,  Sprint and Verizon do both use the same type of wireless technology called CDMA.  A CDMA (Code Division Multiple Access) network uses something called an ESN (Electronic Serial Number) as a way of tracking and identifying a wireless devices on it’s network.  Now unlike GSM phones that use SIM card technology, which has some of the primary GSM network settings stored on the SIM card, CDMA carriers like Sprint and Verizon, preloaded their branded specific phones onto their network to allow them access. With that being the case, if the device’s IMEI is not in their system, it generally will not be allowed to connect to the network.
Finally you can’t “unlock” a CDMA handset, you can unlock the GSM portion if it is a world phone with a GSM chip, but the CDMA portion cannot be unlocked. It can however be flashed, which is a form of programming the device to be used on another CDMA carrier, and it can only have one carrier associated at a time. Current the only carriers that I am aware of that support CDMA flashed phones from Verizon or Sprint are Cricket and MetroPCS. Once a BlackBerry has been flashed, you do run the risk that you won’t be able to use it again on the original carrier’s network. Also email service on a flashed BlackBerry generally won’t work on the new carrier. There are select dealers that can fix the problem but they charge up to $100.00 to do so.
I hope that was easy to read and understand. Unfortunately it is a little more complex than one would believe.
interesting … how about this,.?
what if one were to have two phones ..
one blackberry ..lets say "curve" for sprint ..
and the "storm" ..
in theory, lets say one would have a program
such as CDMA Workshop. and be able to
copy the esn imei or whatever is needed to
activate the phone on sprint from the Curve
to the Storm. Would that be likely to work.?
or is it more than just the esn,>>?