Nifty WordPress plugin lets you view activity on a WP blog in real time: Live. Watch RSS access, comments, misc visitor activity in a little Ajax window as it’s happening.
In a similar vein, discovered Apache Log Tail the other day — integrates with cPanel’s WHM and lets you view tail activity for each domain on a cPanel server in real time – really useful during comment spam attacks, etc. (and way easier / more compact / more visual) than running tail from a shell). Also a big fan of the same developer’s vpsinfo and loadavg scripts.