detect/read/modify RFID tags   (link)

http://www.rf-dump.org/
RFDump is a tool to detect RFID-Tags and show their meta information: Tag ID, Tag Type, manufacturer etc. The user data memory of a tag can be displayed and modified using either a Hex or an ASCII editor. In addition, the integrated cookie feature demonstrates how easy it is for a company to abuse RFID technology to spy on their customers. RFDump works with the ACG Multi-Tag Reader or similar card reader hardware.