They are also good for drying chains after cleaning, blowing general rubbish from bikes. Pumping up the car tyres is a winner too as is blowing blockages out of Hoover hoses.
They are also good when you use the air gun attachment and blow air between your fingers for a comedy farting sound.
The best use is for this. Whack the pressure up and then hold a latex glove over the end of the air gun nozzle and inflate until failure. They get very big and make a pretty load bang when they go. You’ll be laughing for ages (well I did!). If your feeling brave try it with a marigold glove instead. This results in an epically awesome boom! Just don’t be surprised if someone thinks there’s been a gas explosion though!