Depends on why you want them. If you want to invest, I have no idea. If you just want some, find a friend. I had a friend visit from Europe just before I went over there a few years ago. I traded them dollars they gave me pounds when they came over (ie pulled them out on the way to the airport) and we just went online to see the prices. You dont even need to know the person. When in SFO, talking about it with my traveling buddy, a person behind us in the food court from Germany wanted to do the same thing but with Euros. Wish I had had more dollars on me. But this was back when they traded at the oh so painful rate (sarcasim) of $1 to 1.1 Euros.
I work for a european company and people go back and forth all the time. It is kind of a unspoken tradition here. If traveling for buisness, ask a contact coming the other way. Just dont help that poor widow of an ex-african general trying to get outa africa who can pay in gold or diamonds.