Blumels "Shorty" (look best in alloy, but plastic also available) need only the brake calipers to mount. You either like them or hate them, but they do give
some protection from road spray, not as much as full-coverage fenders.
here's a pair on eBay:
http://cgi.ebay.com/Bluemels-Shortie...c4634&x=38&y=6