Robert Anton Wilson was a Lovecraft fan, and we're getting into the Halloween season, so here's a couple of links: Five places that helped inspire Lovecraft and a virtual walking tour of Lovecraft's Providence, Rhode Island.
ILLUMINATUS! has a scene (page 329 of the omnibus edition) in which Robert Putney Drake calls on Lovecraft in a house on Benefit Street. This may be either a mistake or a dramatic liberty; the Wikipedia entry on Lovecraft says that Lovecraft lived on Barnes Street until 1933; 135 Benefit Street is the address of "the shunned house," from the Lovecraft story. Does anyone know if Lovecraft ever lived on Benefit Street?