Another web source of prompts is the livejournal community Darkening Days. One of my favorite recent prompts from there is this Lewis DeSoto quote. It’s a poignant thought, and one that could serve as a marvelous journal meditation or story starter.
Any quote that inspires you can act as an exercise prompt–either through indirect association or through direct inspiration. I can even imagine a character starting off a narration by quoting this particular piece–done right, I think it would be positively magical.