I have installed LAMP on my CritterCam RPi so I can host a little web application written in PHP. I am not using MySQL at this point but being able to run it on the RPi is kinda cool. It is slow but still...!
I followed the install instructions at this link. They are great and so don't need repeating. You can see the results here where LAMP is delivering the preview web page for my CritterCam.