FreedomPop's free cellphone plan is tempting, but we doubt that everyone wants to use one of the carrier's few available handsets. Thankfully, they won't have to. The discount provider has just launched a bring-your-own option that lets anyone with a compatible Sprint phone (CDMA plus LTE or WiMAX) jump on FreedomPop's extra-frugal services. Subscribers who don't yet have a phone are
