A zapper to painlessly but permanantly obliterate people.
On my list would be
Anyone famous for being famous (eg Paris Hilton, Nicole Richie, Tara Palmer Wotsit etc)
Murderers, rapists, paedophiles (think of the money saved on having them in prison)
Numerous politicians
Health & Safety zealots
Ken Livingstone
All Big Brother contestants
Simon Cowell
Pigeons
People who feed pigeons
A neighbour who lets her dogs foul in the street
Andy Parsons
G.P.'s receptionists
I feel better for that!