Dual booting Snow Leopard and Windows 7, although not officially “supported” by the current version of Boot Camp, is possible. Just follow the normal Boot Camp instructions on how to install Windows XP on your Mac and you are good to go.
If you have the latest iMac with the magic mouse, you will notice that the scroll feature will not function using the drivers supplied in your iMac installation DVD. You will have to update your drivers using the Apple Software Update utility. This utility is automatically installed when you follow the Boot Camp installation procedure.