TheCoreWithin

A LASER gun.
http://www.instructables.com/id/EWM4YR2 ... /?ALLSTEPS
http://lifehacker.com/software/diy/turn ... 287252.php
http://felesmagus.com/pages/lasers-safety.html

A Rail gun.
http://www.railgun.org/

I am thinking about trying the laser first...

Apparently those lasers are over 200 times as strong as the sun. (220mW). They can make people blind in less than a micro second if a reflection gets into their eyes.

Maybe I shouldn't build one after all...

..or stick your head into a dvd player.