3d Printing Pen

Came across this today that could have several uses in model building. Essentially, its a 3d printer in the shape of a pen. The pen heats plastic filament and it comes out as if you were writing. So what you 'write' will be in 3d.

Can already see a few uses for this, building roll cages could be a lot easier as your can 'draw' your cage. Could also be used for filling gaps or holes what we would normally use milliput for. This would speed up the process as the plastic hardens in seconds.

May also be possible draw archs etc onto models and sand back the excess.

Any other ideas for this tool.

Heres a link to one of the 3D pens

Thats a great find! I agree, that has some interesting possibilities