Some things to do with pressure sensors Answered
Two projects I'm thinking of will use pressure sensors.
The first is a device that would sit under coffee air pots. There have been countless times when I've gone to get coffee at a self-serve place and there are five pots, but no one tells the counter person they are running dry and I then I have to wait for them to brew. A pressure plate under the pots would control set of red/yellow/green LEDs to indicate how full the pots are.
The second is to use a pressure plate outside the door where your pet comes in and out of the house. It would trigger a doorbell when your pet wants in before it gets a chance to start scratching up the woodwork.