Yea, I answered my own problem.
Change this:
[EdmFunction("NerdDinnerModel.Store", "DistanceBetween")]
To this:
Code:
[EdmFunction("NerdDinner.Models.Store", "DistanceBetween")]
Notice the period between NerdDinner and Models. I think I may have done some other adjustments found in the forum (search for "NearestDinners"). Continue to post messages in the forums if you still have problems. I'll try to help you get through.