I plan to visit a couple of European countries (e.g., Germany, Greece, etc) next year for 2 weeks or so. Do I, a U.S. citizen, need a Schengen visa??
That's what I thought and I travel to Europe every year. But, I keep reading more and more about the Schengen visa and wondered if things have changed on me. So, when, then, does a U.S. citizen need this visa?? For extended travel? Ever??
I think you misunderstand. The entry stamp in the passport of a U.S. citizen IS your Schengen visa, and you do need it upon your entry into the Schengen States of Europe. It's good for 90 days, then you must leave the Schengen area for another 90 days before you can legally return. Say you're flying from NYC to Berlin with a plane change in Amsterdam. You'll get the stamp in Amsterdam when you go through Passport Control and Customs. Once you've got it the clock starts ticking. When you arrive in Berlin it's like flying from NC to NYC, no one will check you, either customs or immigration. It's only when you leave to return to the U.S. that your passport will be checked to see if you've overstayed, and even then they might not bother.
The above post is correct except for one point....there is no universal Schengen "customs." Each country still has the right to inspect any passenger's belongings entering their country . However, it's rarely done.
To answer the other part of your question, yes, you would need a formal visa if:
You planned on staying in the Schengen zone more than 90 days in 180 days. (Possibly as a student, on a student visa)
Planned on working in Europe, for any length of time
Sought permanent residence in the Schengen Zone.
The 90 days obtained just by showing a passport is meant as a convienance, both for Americans, and the Europeans.
There was also a statement made above about the US checking length of stay on return, I think more correctly the Schengen countries will/can check on your departure from Europe, or for that matter at any time during your stay. The US is only concerned about your ability to enter the US.
There is something about US government employees on business needing a visa. Also military people have trouble getting into Switzerland. Better check if you are on government related travel.