Got an old Luxo Jr. style iMac? Sure, it might be obsolete, but you surely can do something with it besides putting it out in the alley for recycling.
Instead, why not do like this guy did, and turn it into a handy Cylon helmet.
All you need to do the same is to grab an old dead iMac, and a Larson Scanner kit from Evil Mad Science, and you’re set. Sure, it doesn’t look quite as impressive as these guys, but whaddya want for next to nothing.