For anyone who's interested in learning more about fasting and prayer (mentioned recently in this post), and their power in the Christian life, I highly recommend reading through this material by the late Bill Bright, former President of Campus Crusade for Christ. Bright observed more than one 40-day fast during his lifetime. The teaching you'll find there is very practical and biblically based.
"Neither be idle in the means, nor make an idol of the means."William Secker