Decent little yogurt and crepes shop just outside of House of Blues/Mandalay Casino as you go into the shops.
Tons of flavors to choose from, from the plain (chocolate) to the slightly more indulgent (cheesecake). They also have a self service bar of toppings with everything from fresh fruit to crushed up candy bars. Sort of a do it yourself Pinkberry.
I liked it, it does get really backed up since it is self service and you can stand there with your cup for awhile while the people in front of you take a year to pick toppings!
Price is in line with the Vegas strip - so expensive for what it is - but it is fro yo in a casino I didn't expect it to be cheap. It was fun. Wanted to try the crepes, but never got a chance - they looked and smelled wonderful!