Prizes for games at my son's birthday?

[~~Daniel's Mommy~~]

I'm going to play a few games tomorrow at my son's birthday. Tape the tail on the donkey, balloon race/dance/whatever and a coloring game. I have a few prizes...just stickers and I was thinking of wrapping them. Would that be silly? Or should I leave the prizes loose and let the children pick them out when they win? I have prizes for everyone, to be fair.
Thanks for your opinions...
Ariana, my son will be 2! And we're having crap weather..lol it's just starting to snow! Typical for May long weekend!