[QUOTE=gsv;2550040]What ideas do people have about the systems for using a DVD like a rewriteable drive. Not the normal burning and erasing. I mean like InCD, DVD-RAM, FAT systems.[/quote]You want DVD-RAM with UDF file system. FAT is deadly.
On XP, you need 3rd party software like either the drivers from Panasonic or InCD (the latest version is now free and works rather nicely).
On Vista and 7, UDF support for DVD-RAM is already included. No personal experience here, since my only Win7 computer does not have an optical drive.