Wow Cuil was a spectacular launch of a pretty average search engine that I'd never use again. It didn't respond very well to many searches, sometimes coming up blank for things that should work.
What was amazing was the level of attention they got. It was on every tech blog and all the news sites I read. Bloody good job getting that much attention though I've no idea why: so it's got ex-Googlers there or indexes billions of pages or is "pioneering". Whoopdee do. Haven't seen that much press since the iPhone 3G.