NeoTron Design (http://lormiller.home.mindspring.com/) sells a wonderful toola really handy laminated key chart. It includes all the new default shortcuts available in FCP 4.
A very usable chart from Loren Miller (the NeoTron guy) is included on this book's DVD. It's based on the shortcuts that work in FCP 2. They're still valid in FCP 3 and 4. Check out this "demo" first and see just how useful this tool is.
Also, dedicated keyboards (with keycaps with the default shortcuts printed on them) are sold at http://www.promax.com. I really like them. They're built on Apple's Pro keyboard.