It was the intro to Shine On You Crazy Diamond, definitely Floyd. Was not Floyd in later broadcasts, which spoilt the joke a bit. IIRC Marvin could also hummed the Beatles version of Rock ‘n’ Roll music.
But hey, this was twenty something years ago I might be mis-remembering.
According to this site I’m not.
I think that’s enough bumping for now.
One idea is that the guy Dirk is following around at the beginning of TSOD is actually Ford. That would have been one way to tie the stories together. There are other links, after all Thor appears in both series.
Just to be exhaustive, read all three books and the short story “Young Zaphod Plays It Safe”. The short story “The Private Life of Genghis Kahn” is also quite good. And, for the record, I liked (and still like) Mostly Harmless. See what a piece of eggshell I have found you.
There is a great deal of P.G. Wodehouse in Bop Ad. The phrase “the long dark tea-time of the soul” is almost verbatim from a Wodehouse story. DNA was a big fan of his, and it shows.
Most people don’t know it, but along with the radio series, television series, books, and upcoming movie, there was an HHG record released (i.e. a black plastic spinny thing). It’s rare, and I’ve never heard it. I’d also kill for a copy of the original radio series, before they edited out the copyrighted songs that they had used when broadcasting it originally.
I saw a trailer for the movie tonight! Woohoo! It didn’t show anything other than the world blowing up, but I was still smiling ear to ear. I almost shouted out YEAH! in the theater.
–Wikkit, past maintainer of the giant alt.fan.douglas-adams FAQ, previous owner of douglas-adams.com, and still with a DNA-themed placeholder at http://www.wikkit.com/
I have had the whole five-book trilogy on my bookshelves for months now, but I haven’t read them yet because of school. I want to tackle them all at once during the winter break. That and “The Da Vinci Code,” which I’ve had for even longer than THGTTG.
I guess I’ll be busy this holiday season. 
The Dirk Gently books are well worth a read too, FWIW.
I think that’s actually from So Long…, which I liked a lot.
Didn’t he call that, "Number five in the increasingly misnamed Hitchhiker’s Trilogy?" Alas, it increases no more.
Definitely So Long and Thanks for All the Fish.
–Cliffy
I used to have the LP!
One of the neat things about the record was that there was a treat hidden in the inner groove loop. (The bit the stylus stayed in if your turntable didn’t automatically return.)
It was Peter Jones (as the Book) revealing: "Arthur bruised his upper arm… Arthur bruised his upper arm… Arthur bruised his upper arm… Arthur bruised his upper arm… " Of course, who else would it have been? 