Reuse postage stamps if they have not been stamped by Australia Post

Keep a look out for any mail you receive where the 50c postage stamp has not been stamped by Australia Post. You can cut the stamp out from the envelope and soak it in water for an hour and the stamp will peel off. Then you can use the stamp by glueing it on the envelope the next time you send snail mail. (Be warned that this is indirectly stealing from Australia Post)