The propellant used in whipped cream is nitrous oxide (N2O) which happens to be a dissociative anesthetic. If you have a can of whipped cream hold the bottle upright and push the nozzle slightly as to allow gas to escape but not the actual whipped cream...you can inhale this gas and hold it. It does get you high for a few minutes, instead of buying cans of whipped cream just search your local supermarket or the internet for "whippets" which contain nitrous.