This is really a great idea and anyone can play along. All you need is a paintbrush and a yellow pad. (I'm sure you can use markers and some printer paper - it doesn't really matter. You don't have to be able to draw, either. In fact it's probably better if you don't know how.) Okay, now that you've gotten your drawing tools, it's time to get started. Simply lay the pad in front of you, pick up your brush and begin sketching out your personal demons.
Pet peeves, addictions, annoying habits, things you hate, things that hate you, important things, silly things, clowns, whatever. As long as they're your personal demons - but they don't all have to be real. Now, keep going until you hit a hundred of them. Then, stop, sit back and take a look at what you created. I'm sure you're going to draw all kinds of crazy things, so I'm not going to hazard a guess. But I guarantee you one thing. It'll be therapeutic.
If you're having trouble with the concept, Lynda Barry has gone ahead and already set an example. She says she got the idea from a sixteenth century hand-scroll painted by some zen monk named Hakuin Ekaku. Neat! Then, she began drawing her demons in sets of ten page strips and collected some of them in a nifty book called, appropriately enough, ONE HUNDRED DEMONS. Mothers. Grandmothers. Vampires. Peer pressure. Hippies. Suicide. Politics. Cicadas. These are just some of the things that keep Lynda up at night, and they all come to life in this hilarious and moving picture book.
And if you're still having trouble with the drawing thing, she provides illustrated instructions in the back of the book. No really, she does.

Peter Aaron Rose is a writer, producer and technologist who lives and works in San Francisco, CA. Under the pseudonym "Peter Siegel", he recently authored Killing Demons, a graphic novel available from Engine Press and Platinum Studios.