If you're electrically minded, basically measure up the diameter and get an appropriately sized CCFL, pull your lights apart and fit it.. if you're not that way inclined, pony up some cash and buy them from Japan where some entrepreneurial sod who is electrically inclined has done just that
http://page10.auctions.yahoo.co.jp/jp/auction/m93193880
http://page4.auctions.yahoo.co.jp/jp/auction/d125846458
http://page5.auctions.yahoo.co.jp/jp/auction/e118052364