Seriously, what can't you make with a 3D printer? For me... my personal Mt. Everest - is to make and use my own 'old school' diving helmet.
Not out of copper! I'll be using materials and manufacturing techniques that most engineers never dreamed of when these helmets were made.
A 1:1 reproduction would be incredible - let's kick that up to amazing.
* Integrated lighting ( http://bit.ly/RlPJIv )
* Micro-printed sub-systems ( http://bit.ly/TNusfC )
* Heads Up Display ( e.g. HUD - http://bit.ly/TpTZpH )
And so much more!