Got a page about one of our mission-critical servers being down this morning around 6:00...I jumped out of bed and headed into the office.  Was here around 6:50 or so.  After having been up for 425 days, the box up and threw a kernel panic.  Doh!  Cycled the power and waited...and it takes a long time to fsck through \~250 gigs.  Anyway - the filesystem check came back okay, and the box is back up now, thankfully before people arrive at work to need this server's services.