One of the vendors on display at Rapid 2012 was Fabbster, makers of a very interesting 3D printer kit. At first glance the Fabbster appears to be yet another RepRap variant, but when you look closer there's a very big difference.
The print material for the Fabbster is not standard, coiled plastic filament. It's sticks.
These injection molded material sticks have a very precise shape. They're square, have teeth along the edges and have a hook at the end. What's the hook for? You can link them together to produce a long stream of input plastic for the printer. Get this: you can link different colors together to produce weirdly multicolored prints, such as the tower here.
The plastic sticks are fed into the heater using the mechanism shown here. This provides extremely reliable and consistent material flow.
But there's more: Because the extruder is so separate from the heater, the metal heater can be brought up to as much as +450C, making the Fabbster capable of printing a much wider variety of materials, even high temperature plastics such as PEEK or even Nylon.
They're still working on the Fabbster's magazine magazine, but we'll be watching to see where this one goes in the future.