Richey Edwards was the guitarist for the Manic Street Preachers, who disappeared in 1995 shortly before the band was supposed to tour the U.S. to promote their then-current album.
Richard John Bingham, the seventh Earl of Lucan, disappeared in 1974, after allegedly beating the family nanny to death and also battering his wife.
Apparently there's some controversy about exactly what happened to both gentlemen.
Very British. I'd've not known at all.
Looks like you beat me to it. Sorry for the double post.