Beginning Nov'14, Sprint customers can attach "ZTE PEEL" to their Apple iPod touch and connect to Sprint's 3G network.
"ZTE PEEL is a unique device that cradles the second- and third-generation iPod touch with a case-like form factor. With universal Wi-Fi compatibility and support for up to two Wi-Fi enabled devices, iPod touch users will have a virtually anywhere, anytime Internet connection that removes the reliance on a Wi-Fi hotspot for a data connection. Customers simply slide their iPod touch (touch-screen face out) into ZTE PEEL, press down on both sides until it clicks into place, and then press the power button located on the back of ZTE PEEL to connect to Sprint's 3G network."
Here's the full press release: