I was using Apache2Triad for a long time but I found a server called Uniform Server. This is a tiny(20-30mb) server which includes Apache MySQL and PHP.
I will be happy to see this program in portableapps.com.
Here is an explanation form http://www.uniformserver.com:
The Uniform Server is a WAMP package that allows you to run a server on any MS Windows OS based computer. It is small and mobile to download or move around and can also be used or setup as a production/live server. Developers also use The Uniform Server to test their applications made with either PHP, MySQL, Perl, or the Apache HTTPd Server.
You can join our forums(http://forum.uniformserver.com) for help and donate ofcourse .
Note: My aim is not advertising.
I tried out the Uniform Server about a month ago and was quite impressed with it. It's great for quick testing of PHP pages and MySQL database applications.
One item on my wish list for it is to have better system tray integration.
Rob Loach [Website] [Projects]