Preheat oven to 350 degrees.
In a medium bowl, combine the mayonnaise, cream cheese, cheddar cheese, Monterey jack cheese, green onions and cayenne pepper until well blended. Transfer the mixture to a small baking dish and spread even in the dish. A pie plate works perfectly.
Top mixture with cracker crumbs and bake for 15 minutes, or until heated through.
Remove the pan from the oven and top with the bacon. Serve immediately with corn chips, bagel chips or crackers. I loved it with Ritz.