Multiple versions? howto?

I have been thinking about how to run multiple versions of a apache+php engine built as a DSO... I figure folks here do this all the time? Anyone have any canned instructions? I figure each individual apache+php engine is running on a port number equal to its version number: http://hostname:410/ http://hostname:411/ http://hostname:412/ etc then the only thing I need to sort out is how to indicate (via the "configure" step) where the libraries of each version's build get put in the file system... and kept separate from one another (i.e. short of doing a mv of he dir) I want to avoid the situation where the previous build writes over the /usr/local/lib/php/lib directory each time... Thank you...