Researchers develop a "scent device" they hope may prove to be a reliable way to detect cancer in patients' urine before it becomes a serious problem.
Keyboard becomes unresponsive on various Apple portables (#2): Fixes
Internal speakers are fine, USB speakers fail.
MacBook Special Report: Keyboard suddenly stops working
Keyboard becomes unresponsive on various Apple portables
MacBook (#4): Keyboard suddenly stops working; Still more on irritating noises; more
Summary of earlier suggestions, along with a new one: try USB Prober.
Almost too simple...
A series of workarounds, organized by increasing severity.
Along with a reminder about suggested fixes.