If you're a user of Ubuntu 11.04 (Natty Narwhal) and are needing to get a full LAMP stack up and running, you're in luck. Omar Abdallah has put together a guide to help with just that.
I wont cover what's new in php 5.3 since it would be another article, however it contains alot of improvements including PHP Namespaces, Late Static Bindings, lambda functions, closures...etc. I would strongly recommend using it. I'll be explaining how to install LAMP stack with PHP 5.3.6 without compiling. It's fairly easy using the dotdeb repository.
He steps you through adding the dotdeb package locations to your plist file and pulling down the GPG key for the connection. The rest is a simple "aptitude install" command away, pulling in the apache2, mysql, php5, mcrypt, curl, gd and phpmyadmin packages.