When Liz and I have travelled in Europe (France, Italy, Spain, Netherlands), we have frequently been mistaken for Canadians.
We did NOT sew the Canadian flag on our bags (which I'm told some American travellers have done) did not tell people we were Canadian. If anyone asked if we were Canadian, we admitted that we were not- but this happened so often that I suspect many more people assumed we were Canadian than mentioned it.
Why did they assume we were Canadian? I think it was because we strove to be very polite. We attempted at all times to communicate in the local language (failing frequently, but I believe the gesture of making the attempt is meaningfuul) and did not express frustration when others did not speak English. If someone asked my opinion of Dubya, I was ready to express my feelings in the local language (e.g. "j'déteste Bush!" in Paris).
Today, I'm a little less embarrassed to be an American. I'm a registered independent and not a huge fan of Obama's, but my fellow citizens did something right yesterday and elected the more reasonable, intelligent candidate.
Here's to President-Elect Obama: May he please give me reasons, when overseas, to be proud of my nationality. May he be successful in overcoming the massive challenges he faces. May he be successful in meeting the extraordinary expectations his adherents have for him.
Most of all, here's hoping that his team governs as well as they campaign.