Perfect Sitemap Generator is a 3 file light based script that will generate a simple XML Sitemap file to send to Google. I've created this after downloading heaps of scripts not doing a correct function to get the files from the folders on my hosting. While also most of them make and array of folders you don't want to scan, mine makes the opposite.
You just have to place the files on your server and declare wich folders do you want to crawl.
The rest is history.