The Kamehameha was an attack from the manga Dragon Ball. If you want to know what it looks like, (hand position, what it looks like, etc.) it can be found right here:
http://www.youtube.com/watch?v=z-N3dIBbDYY&feature=relatedIf the video isn't enough, you can just look it up on google images.
The attack itself should do at least 50 damage. Preferably with a blue laser. If possible, make the hands a couple of different colors, so a guy's hands wouldn't just turn a peachy color.
Ex. Kamehameha- Greenh.
Kamehameha- Whiteh.
You get the point. You would hear a voice yelling: Kaaa-meee... Haa-meee HAAAAA in a high pitch to fit the blocko style.