Ben Melbourne’s UX Designers: Why are we Wasting Time? is a great post on lean methodologies and Lean UX in particular. Of course, I especially like this point:

No amount of text or slides will ever replace the richness of observing your target audience first-hand. Take your client/team out in the field with you, or you’re greatly reducing the value of your research. Seeing a user point out the flaws in your product is the quickest way to convince a CEO to drop his pet feature.