Hummm - lets see.
Home computer, lin/win box. Power cycle regularly, off when not using it, on when in front - so usually 1-4 times in any 24 hour period.
Home server, the last time it was rebooted was when my roommate pulled out the power cord and made me start over on some projects, particularly a rather difficult portfolio website and my mythtv mods

(ummm, bar-b-que mobo!) Word of advice: if your looking for a free power slot, don't pull out a power cable that resembles a strangely thick computer cord connected to a surge supressor backed by UPS. You may anger the *.nix gods (or at least their firey agents)
Work computer: Often need to reboot it as often as I strike a key - I've come to thoroughly despise this winblows box . . .