In a large skillet, brown bacon until crisp, placing cooked strips on paper towels to absorb grease.

For best results, finely chop bacon in a food processor or with a hand blender, but finely chopping by hand will also work.

In a large mixing bowl, blend bacon, tomato and mayonnaise. Add half the sour cream and blend well. Add more sour cream, one spoonful at a time, until the mixture isn't overwhelmed by the taste of mayonnaise (you'll be left with about a cup or so of sour cream, typically). LIGHTLY coat the top of the mix with garlic powder, and blend. Add a dash of salt and pepper to taste.

Toast the bread, then cut each slice into four pieces and serve.