Haha! Same here dude! I have this small Moleskine that I collect quotations with. These days, I use Evernote for my collection. They seriously help augment the comics I make in terms of theme.
Yeah, I used to just write quotes wherever I could in my notebooks, but recently I've taken one of my notebooks and am keeping it as a seperate quotations book. I post quotations at times in my journals, and sometimes use them as springboards for pieces, both written and visual. It gets the mind turning on how to use the idea expressed in those words in your own medium.