[AlexC04]

Perhaps rewriting the database to use MongoDB? Their http://www.mongodb.org/ tutorial took about 10 minutes and is really easy to get to know.

As a DB they say it's designed for SPEED and SCALE. It might be worth looking at. (who's got the time right?) :)

[dasil003]

Alternatively, I've gotten a lot of mileage out of using redis as a cache to selectively optimize data piece by piece.