Folk etymology is a lot of fun, too, ya know. I love sparrow's grass as well as the next person. You, of course, know that St Isidore of Sevilla is your folk etymologist's patron saint? Actually, Izzy is patron saint of computer techies, the Internet, etc., http://www.catholic-forum.com/saints/sainti04.htm, but his book, Etymologiae, is full of all kinds of fantastic folk etymologies, as well as being a fine example of Silver Age Latinity.