Hello. What is the deal with taking prescriptions on these contiki tours and going through customs.

I will be traveling in Europe, Egypt, and Turkey

You can take prescription meds, but having a copy of the prescriotion, or maybe a letter from your doctor wouldn't be a bad idea depending on the medication. It's things like Opiates and sedatives that they can get a bit funny about, but if you can prove they have been prescribed to you it shouldn't be a problem.

Do you need a prescription for oral contraceptives?

A friend who travelled a few years ago said you don;t, but things change so often.

Is there a website to check what needs a script with it?

I checked with my local doctor and he said for NZ you dont need to worry, as long as your not taking in heaps of medications. Got to be more careful if you are say travelling to the Middle east or asia...

If they're in the original prescription bottle you should be fine. As someone else said any opiates and sedatives it might be a good idea to have a letter or prescription. Or if it's anything that you really need it's good to have a presciption incase you lose or run out of medication and need a refill.