M.O.
http://www.ehow.com/how_###-###-####_dye-hair-jello.html
Also I think something like shaving cream would offer a "temporary" spiking hold too. You could try it tonight and see if it holds well when it dries. It may look crispy, but I think it's a relatively safe one day way to hold it. They do have hair products at WalMart that offer SUPER holding power too.
I assume most boys would do the mohawk thing. What about going for the "Wolverine" look (from X Men)? That'd be a cool/modern superhero way that most other boys probably wouldn't think of, but would be super cool.