The 'Rain' ultra-small UHF RFID tag from Murata is really exciting because of its fantastically small size -- it's just 1.25 mm square with a height of 0.55 mm! The tag's tiny composure makes it really well suited to attaching to small or organically-shaped objects with a little bit of glue or epoxy. So what can you do with a small RFID tag? Strapping one to the tip of a Nerf dart to tell if you've hit the target or sounding the alarm if someone removes a trinket from your desk is just the tip of the iceberg.
These tags operate in the UHF (865MHz to 928MHz) band and contains a 96-bit EPC field that is programmable by the user. Using a reader like the M6E Nano with the UHF Ring Antenna will allow you to read/write multiple tags at a range of up to an inch!
To recap these tags are great for tiny close-range identification, just be sure not to misplace them or you might never find them again!