Originally Posted by NW Cat Owner
You also need to make sure it's not going to expire fairly soon either. Some countries won't let you in if your passport is going to expire within say the next 6 months. I'm sure that varies with each country, but yeah, don't wait.
Good point. They want to make sure that you will be leaving again while still legal to travel, to avoid accumulating unwanted permanent visitors.
I went to Amsterdam once without enough advance notice, and had to do it with only a month or so left on my passport - 90 days was the recommended minimum. I was prepared with all sorts to documentation to show that I would be out of there again in on a few days, but in the end no one cared... they barely glanced at my passport. Better prepared than stuck!