Through different methods I have found a inexpensive way to help prevent electrical mishaps. If you get boot grease, grease that goes into the boot of spark plugs, you can apply it to a plug before you plug in. The grease is used to waterproof the plug wires in your car. When you plug into the wall or power strip the prongs will be wiped clean by the friction of the contact points leaving most of the grease on the outer part of the plug effectively making it water resistant.

excellent advice there!

I would like to point out that home depot has an outdoor surge strip with GFI (GFI is via removeable pigtail) surge strip that can be had for around 30 bucks. Having a surge strip that allows you to cover outlets that are not in use goes a long way in keeping water away from the juice as well.

For those like myself who are into serious DIY and some nifty power panel customizations there are gel filled wire nuts that can be had for not much more than the regular wirenuts and a vast array of sealed junction boxes. Also good to point out is when installing outlets in workshop / commercial environments the ground prong is usually on the top (which many would think is upside down). This provides a safety in the event a conductive item (such as a screwdriver) is dropped and makes it between the rubber of the plug and the outlet thus hitting the prongs. The dropped item will fall to either side thus making contact with one side of the circuit and ground rather than both sides of the circuit.

Another interesting thing I've noticed is GFI's can be picky when non grounded items are plugged in that pull high current (some powerheads, heaters, etc). It's usually best to have multiple GFI circuits or a non GFI circuit for these two prong items so that you don't lose power to everything in the event of an GFI "Pop"