I just woke up my MacBook Pro, and the HD sounded like there was something going on. It wasn't the indexing, so I opened up Activity Monitor and found something taking 10-30% CPU called "find". It was under several instances of "sh", and I think it's first parent was "locate.code" or something like that. Anyway, after a while I opened Activity Monitor again, and the "find" process was replaced by something called "makewhatis". It disappeared almost a second after I opened Activity Monitor. Obviously it's just part of the system, but what exactly do these processes do? Apparently "nobody" was running them... lol?