"Premature optimization is the root of all evil"

Very nice quotation from radar.oreilly.com (originally by Donald Knuth):

"It's often frustrating to early developers with big visions when something later comes along and steals their thunder by offering far less. But there's a lesson here: as Donald Knuth says, premature optimization is the root of all evil. And that doesn't just apply to performance, it applies to design. It's impossible to think through what people are going to want to do until they start doing it, so sometimes it's best to seed the market with a hack that gets people going, and then follow up as you watch what they do with it."