The 30th anniversary of Philip K. Dick's death was on Friday, and marked by this blog posting by David Gill at his Total Dick-Head blog.
Dick and Robert Anton Wilson were great fans of each other's work. I believe they met for the first time at Octocon II, a science fiction convention in Santa Rosa, Calif., in October 1978. RAW recalled the encounter, here.
Science fiction book editor David Hartwell also recalled the encounter when I interviewed him:
I went to a convention called Octacon, in California, Santa Rosa. And Wilson was there and I met him. And Phil Dick was there.
And I had a small party in my hotel room, and there were six or seven people. It got down to Robert Anton Wilson and Philip K. Dick talking. And at a certain point, I could not follow what they were saying, and so I just left and went out and got a beer and came back later. They were still talking.
Frank Herbert's Wikipedia bio says he was the featured speaker at Octocon II in October 1978 in Santa Rosa, Calif. Hartwell later recalled to me in an email that it was an Octocon that featured a Robert A. Heinlein blood drive, and I later tracked down a fan, Thom Stark, who apparently confirmed via e-mail that the encounter RAW and Hartwell described was at Octocon II:
I can confirm that I met PKD at Octocon II, at which he was, if I'm not
mistaken, one of two GoHs. I can also confirm that RAH was the featured
attraction at a Red Cross bloodmobile there. (I was lucky enough to work
door security for RAH's day-long autograph session. He and Theodore
Sturgeon sat at a table in the back of the bloodmobile for eight hours
signing autographs, the only requirement for which was that the autograph
seeker had to have at least tried to donate blood. Virginia Heinlein spent
the entire time standing behind RAH's shoulder.)
Stark did not remember RAW at the convention, but he remembered Frank Herbert being there, so the details seem to match up. Here is a link to someone named Ward Griffiths who recalls meeting RAW at that convention.
UPDATE: Griffiths confirms that PKD was a guest of honor at that October 1978 Octocon and RAW was there: "Not sure how your email got to me, but I do recall attending Octocon 2 and briefly meeting RAW there. I don't know whether RAW and PKD were on any panels together, as I rarely attended programming in those days ... but I do know RAW was there and PKD was the GOH. If RAW says they met, they had the opportunity and I'll take him at his word."