Well, i would like to see more people use db as there primary data storage facilltiy.
Why?
Well it makes general administration a lot easier, backup/restore of a broken site is easier, you are contained to upheld the rules of data integerity (upheld by the db) you also got a very flexible solution witch is easy to move/replicate to new sites.

Besides this, when talking about static data, use proxy servers in front of your db server (Oracle got this right). It caches data until it changes on the db, and when it changes the db i queried and the cache updated. Nedless to say that you increase your application speed.
Not sure how to use cache together with MySQL db, but it's probably some solution to that also.

moen