In light of my oncoming "Graduation" from home school/end of first partial year at college/me complaining about my old one for six months, my father, who happens to have been a professional bike mechanic a few times, has stuck together a new set of wheels for me.
Very smooth gears, actual shifters, fatter road tires, and a more comfortable height. This thing is great, yo! 
Very nice!The only thing my own father could make would be...
Actually, a few things, I suppose. A new chair/piece of furniture, maybe even a new bike (he's no mechanic though so he might find a few difficulties), or maybe what he actually does at his job...
A semiconductor... You know, one of the many components of various electronics... Useful, eh?