Anyone thats after a Picoo Z may want to consider these. Made by Silverlit (the very same Silverlit who make the Picoo Z) you get two copters that feature "lasers" and sound effects when you "hit" one another.
They look slightly beefier and of better quality than the standard Picoo Z model though, and you're also getting two for under thirty quid. These are going for £60 for the set on most other sites.
Be warned though, although they dont eat batteries (well, mine doesnt anyway) they wont take rechargeable ones.