http://shipyourenemiesglitter.com/
So you have someone you hate. Could be your neighbour, your ex, Tony Abott or your old boss. For just under $10 AUD, you can send an anonymous envelope packed full of glittery hatred and glitter bomb your archenemy. Works exceptionally well if the recipient has carpets.
UPDATe
Looks like social media killed it. It was too popular for it's own good and the owner of the service wants out.
http://mashable.com/2015/01/15/ship-your-enemies-glitter-reg…
Or you could buy a sachet of glitter from the discount shop for $1, chuck it into a 10c envelope, whack a 70c stamp on it, and achieve the same thing for $1.80.