No subject

Setting your include paths in your htaccess is the easiest to set up,
but on production servers, overides should be turned off - as it slows
down the server (apparently, might depend on setup.).

Using $_SERVER['DOCUMENT_ROOT'] is a smart way though. Unless you move
the site into a subfolder.

And getting back to your origional question, however much of a fiddle
it may seem to set up the virtual hosts, it's probably easier than
adjusting your code to make it work from a subfolder, unless you use
relative links throughout the site - though relative links can lead to
robots crawling oddly and messing your logs.

Grant.