It turns out this is a very simple process and involves creating an open search xml document. From what I understand even internet explorer supports this format.The hardest thing was to get the php icon afixed to my plugin. I downloaded the ico file from http://www.php.net/download-logos.php. I then wrote a quick php script to base 64 encode it so that I could plop it into my xml document without having to worry about hosting the image somewhere.
Unfortunatly, since blogger doesn't let me upload arbitrary files for linking into this post. I had to upload my work to my server. If you are interested you can find it here http://fiwizone.com/alex/phpNet.xml