Creative Mechanics

we've all heard about the horizontal bicycles, three-wheeled motorcycles with two wheels in front, and mecha-striesand. soon i'll have access to a really sweet machine shop with lots of precision equipment (water cutting tool, electron microscope, hammers, the works). i need ideas on what to make and theres no better place to start then with what cool stuff is already being made. what would TFP make if they were in a really souped up version of shop class if materials were free?
my ideas:
wright-flyer cockpit (lying down) on a tricycle with two wheels in the front and a roll cage so that if you go mountain biking and you flip over, you can still pedal and give power to the two wheels in front of you.

lock-pick set

tough case for my laptop/ipod

compound bow

slingshot/crossbow fired the way the daniel craig's wrist gun fires in Cowboys and Aliens

sail-powered craft with wheels capable of traveling over gravel

skateboard with an engine on it

can TFP give me advice on which would be a good idea? what are my bad ideas? how would i go about building my good ideas? how would you guys do it?

 

Rep-rap would be so cool to build!

(http://reprap.org/wiki/Main_Page)

 

Here's an idea, probably a bad one though....