slashdot and memcached
BTW, Slashdot is now running LJ's memcached. They're not using it for everything yet (neither are we: it takes time to port the app), but they're using it to cache rendered comments already.
Also, dormando is working for a client who wants to use it. Exciting stuff.
Anyway, the big LJ speed improvement will come when the new friends view algorithm goes live that uses memcache.