Great substitute for sour creme and mayo in receipes.. plain yogurt! I use it as a dip even. I put a little ranch dip seasoning and a cup of the yogurt. A fav dressing of mine.. salsa ranch. I make my own pico/salsa and when Im ready for some dressing i take some of the ranch/yogurt dip I have and mix in some of the pico and makes a great zesty dressing.
You can also use it as a sauce. mince some garlic and mix in with a cup of yogurt and let it set in the fridge while you fix dinner. The longer it sits the better but it works fine fresh mixed too. Then you can put it over some spicy meat dish, serve it on the side, great on taters.. etc. Let your mind go wild!