There's nothing like real-world usage to flush out the last few bugs, as evidenced by the quick update to Keyboard Maestro 4.3.1, which fixes potential crashes when executing AppleScript or shell scripts, and when using device triggers. A few other minor bugs have also been fixed, and Stairways Software also added support for naming more X-Key keyboard keys and improved handling of negative numbers in the Move Window action. Full release notes are available. ($36 new, free update, 9.1 MB)
Full Screen Quick Look in Snow Leopard
When viewing files in the Finder in Snow Leopard, instead of pressing just the Space bar to enter Quick Look, press Option-Space to display the selected document in full-screen Quick Look, expanding the preview and hiding everything else that would otherwise remain visible.