The key is to figure out why we do the science fair, not just what do we do for the science fair. For most students, it's hard to figure out why they need to bother with the project in the first place. One quick way to become inspired and figure out a good area to focus on is by going through the US Patent and Trademark Office kids website. They have inventor trading cards with biographical information on loads of fascinating scientists as well as 'InventNow.org', an online teaching tool that assists students learn the process of invention. Once you figure out what inspires you, you can easily pick out a subject and a fair project afterwards!