I read about a guy making his own. I don't know if that was on this forum or another one. He bought a pack of jewelry claps (30 clasps in a bag) from a craft store for like 2 bucks, then just cut the barrel and ammo off the imperial guard lasgun and threw the round clasp thing on the end. It is wide barrel looking thing with raised horizontal lines in it. Won't confuse it with any other weapon.
Looks good, is easy, and is much much much much cheaper than buying meltaguns for each little guard dude who needs one.
AH HA! Found the link. It is a guide for a combi-melta but you can use the barrel on anything:
http://www.dakkadakka.com/wiki/en/Cheap_combi-meltas
I am going to use those clasps myself for some Grey Knights melta henchmen so I will let you know how it goes.