Mark Kantrowitz breeds hairless cats. He solves complicated math problems. He collects aboriginal art, folds elaborate origami, restores early battery-operated toys. And then there's the hobby that has turned into his career: knowing absolutely everything about financial aid.
Mr. Kantrowitz, 46, is the brains behind FinAid, an encyclopedic Web site on the topic, and Fastweb, a scholarship search site. He devotes a good part of his considerable mental energy to studying the inner workings of the financial-aid machine, calling attention to its flaws, and explaining it to the rest of us.