Sprint's totally cool with you using your old Pre on one of their MVNOs 16
Got an old Sprint Palm Pre or Pixi or FrankenPre sitting around that you'd like to put to work on another network? Turns out that even though, according to the Librarian of Congress' interpretation of the Digital Millennium Copyright Act the unlocking of cellphones is illegal without carrier approval, Sprint is totally on the side of giving you said approval.
Sprint announced today in a press release that they have no problem with you using your old Sprint phone on another network - so long as it's one of Sprint's own MVNOs (Mobile Virtual Network Operator). In essence, you can use your old Sprint phone on any network, so long as it's Sprint. The list of MVNOs that ride on Sprint's network is actually more than twenty operators long and includes popular names like Virgin, Boost, and Republic. Sprint's touting the option to use your old Sprint smartphone as the "Bring Your Own Sprint Device" program, taking the initiative to lower "the number of inactive phones in the market, diverting phones from landfills." Also, Sprint gets another paying customer without having to deal with the costs of subsidizing a new phone. A growing portion of the customers on Sprint's networks are on these MVNOs, which typically are of the pre-paid no-contract variety as opposed to the traditional post-paid contract system on which Sprint's network was built.
It's worth noting that Bring Your Own Sprint Device, as the name says, only applies to Sprint devices. And that's not just because Sprint hates that Verizon Pre Plus you happen to have sitting in a drawer. While it might be technically possible given the right proprietary bits to reprogram a Verizon phone to work on Sprint or vice versa (we may or may not have be done so with regularity back in the heady day of the Palm Treo), it's a much more difficult endeavour these days. Besides, Sprint wants you to use their phones.