I can't count the number of times that I have had to deal with the "special character" problem. You know the problem--you're reading along on some Web site, perhaps even a Web site that you are managing, and you find words with weird characters--maybe Euro signs, accented upper and lower case characters and whatnot--interspersed with the normal text. Or perhaps the whole page is simply gibberish. Or maybe there is just a stray question mark in the middle of words here and there.
