y'all're underestimating your inventions. Just because there's a commercial product to do the same thing doesn't mean you don't have a full-blown invention. Costing less to make, working better in one way or another, all those kinds of arguments are recognised as substantial by the laws of inventing. You'll rarely find a patent of anything wholly novel--unless you look up mine--but most are particular improvements, and new-use things.

I'm always charmed by commercial objects re-invented to other uses. It can be so elegant. My daughter made a "lap-top" for calculating the elevation of a kite from a video case, a math kit, scientific calculator, a cream-cheese lid, a clock hand, various stuff that fit together as if it were meant to. She also wanted the kite to drop parachutes--she attached army-man parachutes to 35mm film canisters instead--and we found a kite at a Target store that does that, but not nearly as well as hers does. The Target kite has two in-force patents on it!

It would make a great subject for a book--things used for other things. It's really entertaining.