Some guys from the Fishworks project over at Sun discovered something rather interesting, that shouting at a disk array while the array is in use can cause latency on the disks. This does actually make sense as any vibrations can make a difference to the disks as it causes the heads to move a bit and therefore they have to re-read that part of the disk.
I wonder if this will prompt people to make quieter server rooms? Found via this blog post and this one.