I came up with this on the fly, after a HUGE craving for Key Lime pie set in. It's basically the same recipe that I used years ago to make "cherry cheese cake", which came from a magazine. You might want to start out with only 1/3 cup lime juice - then add the remainder, if the filling isn't tart enough. My family and friends like the tartness better, but the key limes are a little mild. Some times If I'm making two pies, use 3 full pkgs of cream cheese. Meaning each pie gets 14oz....recipe is ver versatile.