You can get a pretty reasonable approximation of a DOS box under XP if you try. I know of a few utilities that give your XP dos boxes emulated old-school Sound Blaster 16 support and the like. There's lots of stuff like that on SourceForge. (can't remember the URL - just google search for sourceforge and you'll go right there.)
If you're looking for a front end, try MameWah for a simple one or 3dArcade for that "wow" feeling. (and look on the software forum.)
-EDIT- and if you get your DOS progs running nicely under XP using anything on SourceForge, PM me cuz I've been toying with that as a sort of side project... trying to get my old Ultima Underworld games to work nicely under XP dos boxes.
