For when you need to alert your fellow road users...
I know of several local taverns where you can easily catch crabs for free, but they are rather tiny... Probably 500000 or a million per lb.You can catch crabs for free with a pail and a string.
Go down by the rocks, find a muscle, break it open, tie a string around it, lower it between big rocks (a jetty in the water), lift the string every so often, notice a crab is hanging on eating the open muscle, shake it off so crab falls in the pail.
I think I remember buying live crabs at a swap meet in Orlando Florida for $4 a pound just less than 30 years ago.
It was hilarious when the double brown bagged bag ripped open in the kitchen and a bunch of crabs skittering away on the linoleum floor in the kitchen !!!!!
Samarium Cobalt was also a famous rich magnet.powerful AlNiCo magnets

My first printer had a parallel Centronics Interface, but in 1991 I wrote a C library to control devices via a RS232 serial connection. It is still used today, for RS422 controlled devices, and will stay there for a long time, certainly 10 years or more and far behind me retiring, despite many attempts to get rid of serial devices (they all failed).Who on ASR is old enough to remember the joy of configuring serial (printer) cards by toggling DIP switches and soldering D-9 connectors to cables to get your dot matrix printer to do something?
Show of hands please.
My first printer had a parallel Centronics Interface, but in 1991 I wrote a C library to control devices via a RS232 serial connection. It is still used today, for RS422 controlled devices, and will stay there for a long time, certainly 10 years or more and far behind me retiring, despite many attempts to get rid of serial devices (they all failed).