Preheat the oven to 375 degrees F. Place the phyllo cups on a cookie sheet.
Scoop the cranberry sauce into a small bowl. Stir gently with a fork until smooth.
In another bowl, combine the cream cheese, crab, and onion. Fill each shell with about 1 teaspoon of the cream cheese mixture. Top with ½ teaspoon of the sauce.
Bake for 10 minutes.
Notes
Look for the mini-phyllo shells in your market's freezer section (near the puff pastry). Sometimes they're only carried seasonally (fall holiday time).
If you're counting WW Points be sure to use low fat cream cheese.