March 25, 2006: This looks pretty cool... it's been regularly updated since the initial release last year (which I had tried but wasn't terribly impressed with). It attempts to depict grapically the interconnectedness of filesystem changes and events on your system, which could be very useful for debugging and tracking purposes. This freeware is based on an open-source version of the equally free command-line tool fslogger. Fslogger uses the system-level API that Spotlight leverages in maintaining its search database. The open-source of fslogger is called gfslogger.
Update 4/21/06: OK, it's official... I've moved fseventer to my "Monitoring Tools" folder and set it to launch with my other daily system utilities. Whenever something odd happens to Tiger--like a sudden heavy processing load or other events that catch my attention--I've found it useful (and comforting, usually) to glance at fseventer to see what's going on. This tool is unbelievably fun to watch, in addition to its utility as a system monitor. To help you make sense of what's going on, fseventer displays tooltips--which include system and app icons--as you mouse over the different nodes on the graph. The tooltips also tell you when the item expired (if it's crossed out in red) and when it was last touched. The "decay" rate for past events is configurable, as is the size of the display. All in all, this is definitely worth Zero bucks to have handy, or, as I'm doing, have persistent. Since it uses the same underlying technology as Spotlight, fseventer uses extremely little memory or CPU considering the amount of data it's collecting and displaying.
