Nepomuk/Strigi felt like indexing my desktop to be all semantic-y.  Great... but wow, ~20% CPU for ~12hrs and constant disk thrashing... temperature spiked up pretty bad before I noticed it (not damaging bad, but if there'd been another load on there (i.e. graphics) I'm guessing it would have fried the machine), memory completely exhausted too (on a 4GB machine).

Strigi was just indexing my home directory, doesn't seem like anything that should have caused problems, and yet it did.  Oh well, semantic desktop off for now.