I completely forgot about those, but now that you mention it, I remember getting chased off many times when we would ride our bikes over those trying to get the bell to ring :)
There was something special about using an air pump at the local gas station to inflate your bike tires. I mean, you could use a hand pump back at your own house, but using that pump with the dial-in pressure gauge was just cooler! You'd bring the tire up to pressure with about a 1 second blast.