Flashing Thumbtacks

It's handy leaving notes for friends, coworkers, or relatives tacked up on bulletin boards or the fridge, but if they don't notice the notes, it doesn't do anyone any good. Try calling a little more attention to those notes by using one of these Flashing Thumbtacks to attach it! They're actually adhesive, so they can stick to pretty much any flat surface, and when you push them all the way in, they flash brightly using their built-in battery and LED. $3.99 USD. (Via Gizmodo.)