It is possible to get 24" on your bike, but the geo will be wacked up.
Your bb will be lower to the ground, and it will be easier for you to smash your frame on the ground because of it's low clearance.
What's so bad about 26", anyway? Changing wheels will only lower the weight slightly (if that's what you're after), and it wont make your bike any easier to use at the skatepark...