I've only ever made this to go with our hot wings, I've never tried it on salad, but considering how good it is on hot wings I can only imagine it would go well with other things also.
1/2 Cup plain yogurt or dairy sour cream
1/4 Cup cottage cheese
1/4 Cup mayonnaise
3/4 Cup crumbled blue cheese
1-2 Tbls milk
Combine the sour cream/yogurt, cottage cheese, mayonnaise and 1/4 cup of the blue cheese in a food processor or blender. Puree until smooth. Stir in the rest of the blue cheese until well mixed. Add milk until it reaches the desired consistency.
Source: Better Homes & Gardens cookbook