This is one of my favorite dips to bring to a party and it's always a hit. It is delicious and creamy and has just the right amount of crab so it doesn't overpower the other ingredients. The tomato on top gives it a little extra burst of sweetness. Serve it with bread, chips, crackers, vegetables, etc., for dipping. You can make a lighter version of this by substituting the sour cream and mayonnaise with nonfat plain yogurt. For a vegetarian version, simply omit the crab.