Gas Pumps
Pumping gas can be an absent-minded activity. That being said, there have been accidents where drivers leave the nozzle in their car and speed off by mistake. If that happens, there's a part of the pump that is supposed to break off to avoid any major accidents.
Padlock Holes
The holes on the bottom or sides of padlocks is used as an orifice to insert lubricant in case the lock gets too rusty to use. They also allow for dirt and water to seep through the lock, again helping to avoid rust.