I've always chosen mustard over ketchup but recently rediscovered mustard, not just as a spread but as a dip as well. It's really low-fat and not very caloric, especially in the whole grain form, which is less processed than a yellow mustard. Whole grain mustard also has a nice kick that isn't as strong Dijon.
Just mix them all together and serve with pretzels, breadsticks or vegetable chips for a healthy snack or appetizer. Save the rest for a turkey sandwich on wheat. Done and done!