Say what you will about the cavalier bike messengers that give cyclists a bad name, but it doesn't change the fact that pedaling your way to work is better for both your health and the environment. Unfortunately, biking (especially in New York City) can feel a little, well, dangerous at times. MYBELL isn't magically going to keep you from getting doored while flying down Broadway, but the extremely loud electronic bicycle bell should make you a little harder to miss. Inside this little box is a powerful audio amplifier that plays custom sounds at up to 96dB -- your average mechanical bell tops out at 70dB. It also includes LEDs that can be programmed to flash in a pattern unique to you. Of course, none of that is going to keep careless motorists out of the bike lane, so you'll still your wits and quick reflexes, in addition to MYBELL.
You can see all of the Insert Coin semifinalists here.