The Watson family’s experience is not an unusual one. The use of ““stealth URLs,’’ slight spelling variations on the addresses of popular Web sites, is the latest Internet strategy for increasing visits by potential subscribers. Trying to find Motorola? If you’re not interested in photos of hard-core sex, don’t hit the ““r’’ key twice. While typing www.altavista.com, clumsy fingers could present you with ““over 25,000 nude pictures.’’ And be sure not to leave out the ““e’’ in www.oracle.com.

Preying on bad typists is not yet illegal, but soon it may be. New York lawyer John Delaney says there are two trademark issues: consumers may be confused, and copycat sites may dilute the value of the original name. When judges begin to rule on pending suits, predicts David Abraham, a lawyer with Wilson, Sonsini, Goodrich and Rosati in Palo Alto, Calif., ““the sleaze factor will be tough to overcome.’’ In the meantime, spelling lessons may be a parent’s best defense.