To get quicker load times on the raspberry pi, what I've found helps is to use a lighter weight webserver. What I've used in place of apache is nginx. I hear monkey is even better, however they don't yet have a release arm build.
Here are some numbers.
http://raspberrywebserver.com/raspberrypicluster/comparing-the-performance-of-nginx-and-apache-web-servers.html
Additionally I've used mongodb instead of MySQL because of it being quicker for more specific use cases. I'm certain that it isn't always the solution to go with however, as it radically changes how you would store your data and makes multi table relational queries a pain.
MySQL vs MongoDB 1000 reads
Finally make sure you have a fast SD card, and you can turn on a swap file or swap partition to help with only having 512 megs of memory (model b).
Of course if you are using the pi to develop for a specific environment you may not have any of those options. But if you want to use it for a personal web server or have more freedom with the production environment, that's the route I'd check into.