Seems wupi might see open sc/cf/mmc/flash card readers. Remove in usb or might have to open case. I guess it could be a sata adapter deal but most are supported.
I suggest you consider virtual machines if you have a new enough system.
Second best is usb flash drive installs. See www.pendrivelinux.com
for many how-to's
$8 for a 1G flash and you can load plenty and not be too worried you will bork your Vista install. Usb flash drive or usb external are good in you be sure that the boot loaders of syslinux are placed on the external drive and bios boot order is set for the usb drive first to prevent overwrite of ms loader.
Don't forget live cd's are pretty good too.