The ammunition box is a great idea! Then after you destroy your expensive videocam, you can always use it to hold rounds and go off and shoot yourself! lol ;)

Gotta vote with Dave here - really cheap underwater housings lead to really expensive, electronic paperweights.

Wet CENTAL AMERICA Cheap Wet box.....
 

Hi,

I also made the underwater cheap box. I will not take my camera underwater with it, but I use my Wall Mart Sport Utility Box ($8.00) for keeping the camera dry in a boat. Inside I use pool noodles to brace the sides of the camera. I should have used this in my hike in the rain forest in Central America. Good luck, and do not go underwater with this thing!!!


Ken...... the $900 repair bill dude.........

Camera waterproofing under 20 bucks
 

Cheap disposable and light weight waterproofing under 20 $
Years back when I was playing with super 8 film surfing and sailing, we made a disposable housing that worked great. The small cameras of today with wide angle lenses and the availability of plexi glass that can be formed easily leads to a number of modifications to this simple waterproofing system.
You require
Latex glove
Round or oval tempered glass or plexi for a lens port, must be bigger than the hand hole of the glove.
Silicon rubber glue
Tape to secure all in place
Method:
Pressure tests the glove, first blow the glove up makes sure it has no leaks or pin holes.
Make sure that the camera has fresh batteries and tape inside and is ready to go, take the strap off and anything else removable that is not required.
Stretch the glove, and place the camera inside.
Make sure your glass port is clean, stretch the glove again and fit in the lens port make sure it goes well in and you have a good overlap to glue down to the port.
Glue the glove overlap to the lens and press down firmly and trim when dry
Use the tape to secure the camera in position, make a tape on a handle if required..
Mark

This would be a one time housing wouldn't it ? Once you use it you have to destroy the glove to use it again..

dissposable housing
 

Yes one time use, light weight and simple to rig, and easy to carry, and a once you have a glass port the gloves and silicon glue can be brought nearly anywhere.
Mark

Here's the direction I went. I know it's not $20, but for $170 you can reuse it, protect your camera, see the LCD, and have full control (if you have LANC):

Amazon.com: Sony SPK-HCD Waterproof Sports Pack for underwater use with DCR-SR220, 45, 55, 65 Camcorders: Electronics

Its designed specifically for the Sony mini HDV's such as HDR-HC3, but has a zillion adapters and I've read it will work with Canon HV20/30 as well. There are similar housings for point and shoot cameras as well (cheaper also).