Crowdsourcing, crowdfunding, or whatever verb you want to call it, has a unique immediacy that excites the public and everyone involved, even if they have nothing to gain. One of my favorites is Goldiblox, an engineering toy designed to appeal to girls.
Since this blog is cycling oriented, I'll get to listing the products of greatest cycling interest.
Spurcycle makes a great handlebar bell and GripRings that add up to a full sized grip, adding style enhancement to your bike.
Rubbee gives your bike an electric motor with no muss or fuss.
Free2Go is a very portable single bike carrier for Smart cars, of the Car2Go variety.
BikeSpike is a GPS tracker for your bike, in case of theft.
There are plenty of lights, locks and fender systems that give riders new ways to stay stylishly clean and seen. There are many books and other media to learn and enjoy the pleasures of two wheeling it.