I just made this. I LOVE blue cheese, but let's face it, it is definitely not low calorie. I have a fresh batch of homemade yogurt in the fridge and I decided to experiment. It was actually pretty good...and much lower in fat than regular blue cheese dressing/dip. I will definitely use this again.

plain yogurt
blue cheese crumbles to taste
fresh ground pepper to taste
salt to taste
squeeze of lemon juice or dash of vinegar
lemon zest (optional)

mix together and chill for a while to let the flavors blend.