Sprint still really, really wants you to switch to its phone network. To that end, it just launched an offer that reimburses whatever it costs you to hop aboard, whether it's a contract termination fee or device installment payments -- there's no cap, as with other switching promos. The only big catch is that you have to turn in any existing phones. So long as you live in an area with good Sprint coverage, though, this could make a lot of sense if you're frustrated by another carrier and would rather not drop hundreds of dollars just to jump ship.