Google Knol may or may not ever come to fruition, but Hitwise was kind enough to put together this chart of its potential rivals in the market for websites which answer your questions. And yes, Jason Calacanis's Mahalo is on there. You have to squint. It's way, way, way down there at the bottom. That little sliver of green. No wonder Calacanis is always commenting here with a link to the site. Think he'll do it again on this post?