I’ve started to read through Frank Chimero’s essay on “What Screen Wants“; a definite must read! I liked this part in particular:
…a comment field with progressive disclosure. This method allows the designer to reduce UI components to their essence. Input forms are only revealed when necessary to avoid confusion, and the animation aids them in understanding the origin of the new form fields.
Progressive disclosure. I like it. You only disclose the info to the user when he needs it. That way the UI is more contextual, more simplified and create less confusion.