Many of the digital cameras companies have waterproof cases designed specifically for their units.  They are usually made of clear polycarbonate and have a rubber seal to keep the moisture from getting to the innards.

That's all great, but the cost for all this customization is usually not cheap.  However, the folks at AquaPac have a lower cost solution for the occasional snorkeler.

Another benefit of these AquaPac is, unlike the custom cases, you won't have to get a new one when you upgrade your camera! 

For $30 each, you can get a few of these little beauties for what you would normally pay for one custom case.  Buy them directly from AquaPac or at your local REI store.  [More...]