I'm on a mission lately to make LiveJournal really damn fast. I've had a wave of ideas on how to speed up parts. Yesterday I changed the way friends pages were constructed. Today I changed how user pictures are stored internally. I also limited the number of interests you're allowed to have to 150 because the "find a user like me" code got slow when the number of interests was too high. Nearly everybody was under 150 but there were 50 people or so that had up 1,600. Gimme a frickin' break.
Tonight I'm going to be working on speeding up the directory search.