A long time ago I managed to set up pretty much all temporary files, internet cache files, and even system log files in a tmpfs RAM volume. Made a HUGE difference!
That last part, putting log files in tmpfs, is not exactly easy though, it requires a startup script to generate all the log directory names, otherwise the system will most likely crash. Plus you lose all system logs after every restart.
Still, tell ya what, it was worth the effort to me, made things so much faster!