Altoid tins are super popular as enclosures for a whole variety of different electrical projects (i.e. USB hub, iPod battery charger, a set-top box, the list goes on). They're just the right size for a 9V battery and a small PCB, but this is the 21st century; 2"x3.5" is child's play. I want to start seeing projects that fit inside the ultimate SMT challenge: Altoids Smalls. They're 2.5"x1.25", 70% as tall, and a whole hell of a lot more impressive.