XMLConnector: absolute vs relative URLs

I am running apache on OSX to develop a flash/xml/php/mysql content management system. I use the XMLConnector to pull xml from a php script (that accesses mysql). Running locally on my machine, I have to use absolute URLs in my XMLConnector component. But when I upload it to the server that also runs apache, relative URLs work. I would like to only have to use relative, so I don’t have to modify all of my scripts before I upload them. Any suggestions?
thanks
-jeff