Sam has written a feature to allow SilverStripe to install without mod_rewrite. This will aid installation on IIS 6, Lighttpd, Zeus, and for those with Apache who can't get mod_rewrite working. When installed in this way, you get semi-friendly URLs of the form www.silverstripe.org/index.php/my-page/
Please read http://groups.google.com/group/silverstripe-dev/browse_thread/thread/f0c082132f3f1014
We hope this removes a lot of pain for those wrestling with mod_rewrite - it is a common topic in this forum!