WISP, the Wireless Identification and Sensing Platform, is a family of sensors that are powered and read by UHF RFID readers. WISPs do not require batteries since they harvest their power from the RF signal generated by the reader. The WISP is an open source, open architecture EPC Class 1 Generation 2 RFID tag that includes a fully programmable 16 bit microcontroller as well as arbitrary sensors. Unlike the WISP, conventional RFID tags are black boxes that cannot execute arbitrary computer programs and do not support sensors. We have given WISPs to collaborators around the world. Many of the applications have been sensing related, but we were also surprised to find many applications in the areas of cryptography and security that were enabled by WISP's programmability.