Many utilities for tweaking hidden settings and performing maintenance let you access OS X settings and features that aren’t otherwise easily available. Among these products, TinkerTool is one of my favorites. TinkerTool provides access to many secret settings—for the Finder, the Dock, Exposé, system appearances, and much more—as well as scores of system maintenance and customization options. But developer Marcel Bresink has taken much of the risk out of using these utilities by separating safe actions from potentially risky ones. User-level preference settings are available via TinkerTool (which any user can run).