Professor Albert Hoffman, January 11, 1906 – April 29, 2008ce.
Dead at 102.

If you ever did acid, you owe him a debt of thanks.
If you ever liked music or art made by someone who did acid, ditto.

I had the honour of meeting him at a conference in 1998. Little Swiss guy in a suit, looked thirty years younger than he was. And he glowed. Nearest thing to a Bodhisattva I have ever met.
I shook his hand and asked the only question I could think of - "why didn't you fall off the bike?"

He mattered.

As many of you know, Gary Gygax, co-creator of Dungeons and Dragons (and thus a huge influence on my life) died this week.

Here's what XKCD had to say:
http://xkcd.com/393/