Eurailing will change your life or at least your perspective on life. It was on a Eurail pass at a train station in Nice that I met Chika and Iako, rode to Roma and ended up in Yokohama Japan. Eurailing can be a great adventure for people of any age. If you're young take a break before settling down to a career. For families it makes Europe affordable. And retirees, start your second youth.
Eurail passes can pay for themselves. By traveling on overnight trains you can save on 10-15 nights of hotel stay. Be sure to buy some food and drinks at the market before the train-rideThe trick to get a good night's sleep is to show up an hour early for your train and grab a whole compartment for you and your buddy. If the train isn't too busy, fold down the seats to make a comfortable private sleeping compartment. Otherwise learn to make yourself comfy sleeping sitting upright.
Planning and researching can be a big part of the fun. I recommend Rick Steve's Europe through the back door for a some ideas on different ways of exploring Europe.
Take advantage of Europe's market to sample local favorites and save money.
Stay at camp-grounds instead of hotels to save money. The Bois de Boulogne campground right in the heart of Paris is only 16 Euros for 4 people.
Eurail flex-passes make the best option for most people. Flexipasses are good for travel 10 days in or 15 days in 2 months valid in 22 countries in Europe. Passes are less than $1000 for the adventure of a lifetime.