Mike Williams for his outstanding Google Maps API tutorial and fine pushpin icons. Mike's preferred charity is his church's Business For Life program, which which helps people in third world countries to help themselves by providing an individual with a grant to start up their own business. Drop by and make a donation!
Dynamicdrive.com for the spiffy "link floatie" function which I've used for popping up info windows
Andre Lewis for the the Gzoom control which provides the click-and-drag-a-rectangle-to-zoom function
Tom Mangan for his TLabel extension for adding labels to the map