The folks at Nobis have come out with an adjustable hat for the one size fits all market.  Instead of they typical snap/strap at the back of the hat, they have a button sized dial on the right side of the hat.  Turn the wheel and an internal strap adjusts to size.

Not exactly an earth shattering gadget… but a gadget none the less.  Check out the crafty names of the Nobis hats here.