This is a 12 part series on Backpacking Europe from TravelPUNK.com for all you aspiring & seasoned backpackers and student travelers.
2. Passports and Visas
Most of the European countries are covered under Schengen visa although you may need to apply for independent visas for some.
For Americans, the rules are clear on the length of time you can travel Europe.
The U.S. Department of State says that “you can travel Europe for business or pleasure for 90 days. That 90-day period begins with entry into any of the “Schengen group” countries: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, and Sweden. Multiple visits to Schengen countries may not exceed 90 days in any 6 month period.”

Back in the day, you could pretty much extend this period by overstaying as you wish, without worrying much about the ramifications.
Today, things have gotten a lot stricter and I’m not sure you want to test out Homeland Security these days.
As part of your pre-travel preparations, make sure you make clear photo copies of your passport and any and all visas.
Then, email those copies to yourself, by creating a “dummy” email account.
For example, if you have a Yahoo account that you always use, then open up a Gmail “dummy” account and email these copies to that account. You will ONLY open that account in the case of an emergency (hopefully never).