There's a way to change my icloud email address, right?

You cannot change your primary iCloud email address, if it end with @mac.com, @me.com, or @icloud.com. If this is not the case, then you could change it just here: https://appleid.apple.com, but before you do, please make sure that you signed out of iCloud on all your devices and turned off "Find My iPhone" in order to prevent future conflicts like locked iPhones, iPads, Macs.

David has described how to change the address which you use as your Apple ID and therefore your iCloud login. Or were you asking about changing the @icloud.com email address which is provided by the service? Once you have created an iCloud account and chosen an @icloud.com address to go with it you can't change the address (short of creating an entirely new account).

However, all is not lost. You can add up to three 'email aliases' - these are additional addresses (not accounts) which deliver into the same inbox as the main account. (New aliases can only be @icloud.com ones; @me.com addresses cannot now be created.)

You should be aware before you start that once you've created an alias you cannot turn that address into a full iCloud account or move it to another account.

More information on aliases here: http://help.apple.com/icloud/#mm6b1a490a