Haven't seen any contacts replacement apps but I use ABCOrganizer (think it's renamed FolderOrganizer) and have a 'Direct Dial' folder on my home-screen. Just open it and one click and it calls, then upon returning to the home-screen the folder is closed. Also gives several other great features, def worth the $2 or whatever it is now.
But which is better:
either of the two mentioned already,
or
Apps Organizer,1.4.8 Organize your Android applications using labels.You can create a label shortcut (or a widget) with a custom icon on Android home (long touch on home and select shortcut) 1.5: widget support, if you have "Apps label" bug please use widgets instead of shortcuts. Latest version: 1.5.1 (for all Android versions)