Matt,
Thanks for your input. I forgot about migrating across heterogenous operating systems which is also very important for me since I have a mix of Windows in all flavors including a Win2003 Enterprise Eval right now, Red Hat Linux and a Sun Blade with Solaris 8. Since you mentioned the \opt directory on 'NIX systems, I think I'll even start putting XAMPP in an "C:\opt" folder on the Windows systems to maintain folder structure across all systems.
Cheers,
Bob