Upon searching the net and sites like youtube I was MORTIFIED at the terribly wrong interpretations of the Tzatziki recipe by people who obviously had never been to Greece..
Some recipes included red-peppers and even feta-cheese (!!!) in the sauce.. which may be an interesting proposition.. but ask any Greek and they will tell you that it sure ain't tzatziki!!!
Here's a short video I found that shows the authentic traditional recipe. Nice and simple! - Enjoy!