Hi, just got this very interesting article from Ron Scott, Editor at forexinterbank.com:

Living in northern Florida, I have a tendency to be pretty complacent about hurricanes and that's because they don't arrive here without plenty of advanced warning which is more than can be said for power outages. It's a rarity but a power outage can occur at any time anywhere in the world so every trader is well advised to think about the implications such an event will have on his/her financial well being. If you use mental stops and don't have a contingency plan, you might well consider taking a few simple precautions to avoid a financial catastrophe that could bite you in the bippy..

Online trading, as we all know, is totally dependent on the availability of electrical service - your computer, your internet connection, and the availability of telephone service. If you use mental stop losses and haven't thought about what you would do if you experience a power outage, here is a contingency plan you can put in place in a matter of minutes. 

1. Know what safeguards, if any, your broker already has in place. While some brokers will automatically close out open positions when they reach a certain percentage of your margin account, many do not. It's important, therefore, that you familiarize yourself with the broker's policy regarding negative balances. If your risk is not limited to your account balance and, therefore, virtually unlimited, you will need to have a way to close out your positions should your computer freeze up or you lose internet connectivity.
    
2. If you lose electrical power, you will undoubtedly also lose your telephone land line as well. As a result, it's highly recommended you invest in a cell phone. Power outages are usually very localized so if you lose power you will probably still be able to contact your broker's trading desk because most cell towers have backup power systems.
    
3. Obviously, to complete the process you might take the addition precaution, programming the telephone number of your broker's trading desk into both your home telephone and cell phone.  At the very least you'll want to have that number at your finger tips so you can contact them immediately. To do that, of course, you will also need your account number so write it in your day planner and keep that handy as well.

I personally have only experienced two power outages in the past ten years and on neither occasion did it concern me because I rarely submit an order without placing a stop loss. That being said, on those rare occasions when I am trading with mental stops, I trade with confidence knowing I have at my fingertips the means to immediately contact the trading desk to close my positions.