It was Douglas Adams's 54th birthday (or it would have been, were he still alive..) on March 11th.
Reading Industrial Technology & Witchcraft (german), I found references to Douglas playing guitar during a Pink Floyd concert:
"Adams's official biography shares its name with the song "Wish You Were Here" by Pink Floyd. Adams was friendly with their guitarist David Gilmour and, on the occasion of his 42nd birthday (the number 42 having especial significance, being The Answer to Life, the Universe and Everything), was invited to make a guest appearance at one of their 1994 concerts in London, playing rhythm guitar on the songs "Brain Damage" and "Eclipse". Adams chose the name for Pink Floyd's 1994 album, The Division Bell by picking the words from the lyrics to one of its tracks. Gilmour also performed at Adams's Memorial Service."
Ok guys, that's not bad. Now where are the videos?