Here's a sweet steampunk raygun, homebrewed from camera and radio parts:
Make a Steampunk "Atomic Disruptor" Raygun from Old Parts
The Atomic Disruptor Raygun is straight out of steampunk fiction. The cool DIY raygun has been put together by Cohophoto entirely from old radio and camera parts. If you are looking for a slice of futuristic fantasy, Cocophoto has illustrated the project on his Flickr photoset. Though short on words, the pictures show the construction details of the gun.