It’s really more half-a-Triscuit-sized. This little 1.2″x0.7″ $20 board is a good solution for your home projects that require a little computation but not a lot of space. Say you want to put a little RFID detector in your door that unlocks it when you come near. Don’t need a big hard drive-sized package nailed to the door; with a Teensy you could practically embed the system in the doorknob.
The Teensy is Arduino-compatible, so you won’t have to revamp your whole DIY lifestyle and learn a new platform. It looks super easy to connect and comes with tools to load its 15.5K of memory with whatever good times you’ve got planned.