A few weeks ago I took a shot at magnet fishing in the bay next to our apartment block in China.
I created a hasty setup using some neodymium magnets, a twist of fire and about 20 metres of bungie cord.
I also purchased some gardening gloves and got Ms. 7's assistance to ping it into the 'water'.
We caught a Red Bull can, 3 bottle caps, fishing hooks, a key, 50 metres of drift-net and two 1 cent coins.
This idea just paid for itself.
PS - I've just received this larger magnet from dx.com. Will post more treasures soon.