Progressive Disclosure on Web Apps

[oombrella[at]gmail.com]

One of the topics brought up at the last meeting was progressive
disclosure in interfaces. Succinctly, this is the method used to
expose UI functions as a person interacts with a piece of software. An
example of this is when a menu shows (i.e. discloses) more functions
as a person uses them.

While this has been a common pattern in client-side apps for some
time, I was struck that I haven't seen this occur as much in web apps.
Personally, I couldn't think of any cases where online software
exposed my most common actions. This is huge area that appears to be
under-served.

Does anyone have any examples of this?