two thoughts
1. people seem to be asking me "what time is it?" a lot more often than they did before my watch stopped working. This is strange. I can't explain it. The only explanation of this that I can come up with is that all of a sudden I've started passing better and people are more likely to ask women than men what time it is. But that seems awfully far-fetched.

2. vending machines seem easy to beat somehow. I pay for something in a vending machine with quarters. Now, the vending machine knows that these are "quarters" because the size, weight, and some sort of electromagnetic signature (which arises from the chemical composition of the quarter) are correct. But if coins are just flat metal disks, and the metal in a quarter costs less than 25 cents, then what's to stop me from making my own quarters that would be good enough to fool a vending machine? They wouldn't have to have the fancy stamped designs on them, and it can't be that hard to make metal disks, can it?
The reason there aren't cheap "vending machine quarters" out there is probably that the equipment to make them still costs too much, and you'd have to make too many quarters to regain your investment. But it's an interesting thought.