In the meantime, a quick Google search brought up this article from last year, apparently before Howard died:
Vidal and his companion, Howard Austen, spend part of the year in the Hollywood Hills and also own a sprawling villa at Ravello, Italy. The Hollywood house faces busy Outpost Drive, but entering the driveway you seem transported into a rain forest. Towering pines, verdant ferns, ivy everywhere. The foliage partially hides a traditional California white stucco and red tile-roof house that Vidal has owned for 30 years.
Why live in Hollywood when he has scant regard for the place?
"Cedars-Sinai," he replies succinctly, referring to the hospital of choice for many Hollywood celebrities. He has been plagued with an arthritic knee that for a time prevented him from walking. A knee operation, daily swims and muscle massage has allowed him to hobble, but more surgery may be needed. "I don't want a plastic knee," he insists.
His face is lined, but he has all his hair, which he says has become fine and unmanageable with age. His mind remains agile, and he tosses epigrams like confetti.http://www.thehollandsentinel.net/stories/072803/ent_072803081.shtmlA few years ago, that trick knee put him in a wheelchair, making it hard for him to get around the world to attend his various engagements. In the post-911 airport security environment, it was becoming extremely taxing for him to travel via airports--he hates the eroding of civil liberties in all it's forms, particularly through invasive identity hoops and phony terrorist homeland security hoops that airport security were constantly making him hop, in his decrepit arthritic state, through. They would take his wheelchair apart, piece by piece, for example, looking for the terrorist hijacking bombs he no doubt had stuffed there. I guess he couldn't take it anymore--he is not a young man--and he just decided to stay home, mostly in Hollywood Hills, and do as much work as he could from there. This is why, over the past year and a half or so, you see him speaking at anti-war demonstrations in LA and you hear him from time to time on Pacifica radio, giving these personal, Gore Vidal fireside intimate chats from high in his perch in the unfashionable Hollywood Hills.
He used to go to the house in Italy mostly in the summer to write books, but from what I can gather, since Howard Austen died, he doesn't seem to have been back there much. He always seems to be stateside. He has the plastic knee now, and so he can get around with a cane, I think, but without wheelchair.
Somebody said he was guest on Tonight Show last Friday night, with Susan Sarandon guest hosting. There might have been I thread here on DU. I don't know.