Amsterdam -- ignore the junkies.
When walking thru Der Wallen (what tourists call 'the red light district' - there are actually several, but the old part of the city is what people are talking about 99% of the time) ***NEVER*** buy anything from the street dealers. Don't even think about it. When you walk by someone saying 'Coca Coca heroin coca ecstasy coca' say 'nay' and keep walking. 'Nay' is Dutch for no, and the street dealers know that if you know enough to say 'nay' you're not going to buy anything and leave you alone. Some of them may try to block your path and get a little insistent, keep saying nay and keep moving and they'll let you by.
I highly recommend a trip to the PIC (Prostitution Information Center). It's in the very center, right by Oudekerk (old church, oldest building in city) in an actual red light window room. Even if you're not interested in partaking in the services of the numerous ladies working the area it's a good informative stop. The lady that runs it is a former prostitute and very nice, answer any questions you have about the laws, practices, unions, negotiating with prostitutes, how to rent a window to be a prostitute, etc. You can go in the back and see the little bedroom where the deeds are done and the panic button on the wall (yes they have security for them). They teach classes there (for men and women) on how to be a prostitute too. They also have some of the best souvenirs around, including Delftbleu china dutch houses with girls painted in the windows.
Unless you like standing in lines for hours to look at empty rooms, avoid the Anne Frank house.
