Dance...stick on your fave music (well, unless you like classical or something) and jig about for half an hour while getting ready for school. Not only will it keep you fit but you'll be in a good mood all day too...so your friends also benefit. Alternatively, just walk up and down the stairs 20 times every morning...up for one shoe, back down, up for the other shoe, back down, up again for one book, back down, then another...and so on. But...my skipping rope is my bestest friend..