Apple released a free update to Mac OS X 10.5 Leopard today. This update, (10.5.1), provides a wide array of bug fixes and other changes as detailed in this Apple support document. At this time, we are not aware of any accessibility enhancements or changes as a result of applying this update. If you find any, let us know. The update is free and recommended for all Mac OS X 10.5 Leopard users. To update your machine, choose the "Software Update" option in the Apple menu.