Gold has been used throughout history as money and has been a relative standard for currency equivalents specific to economic regions or countries.  It is the most popular hedging instrument againts economy.  When bad news starts coming to market, gold price starts increasing.

Here is a chart og gold price from Jan 2000 to  August 2010.

Trend is definitely upword and few investors might dare to go short in gold. However gold has been volatile for last 3-4 years.  You can see it from chart from begining of 2006 to end.

My idea is to make money when gold price falls.  Only way I can do it by going short for a minimum period (Say 1 day).

Strategy:
If gold price is going upward continuously for a  good number of days, there is a possibility that the trend will break on the next day.
I  used  data from 2006 to 2010 and put a threshold for each up-move to make sure the trend is strictly increasing.
Looking at  pevious X days return and going short for a day, I got good return

Average return: 0.43%

Total number of trades: 21

No of possitive retun: 17

Standard deviation: 0.87%

Win rate: 81%

This is the chart for wealth

I could not get more signals, however you can look back less number of days and adjust threshold to lower level to get more  number of entry signals. 
[I could get only 21 entry signal from  2006 to 2010 and I have not used any transaction cost. Strategy may not work for future time period. ]