modal popup settings windows, where are they?

In the past I have seen in my own blender and in online posts examples of modal popup windows with settings for various parameters associated with specific tasks but for the life of me can’t find an example. Sometimes the non-overlapping window paradigm is not the most efficient. Right now the only vague recollection of examples are the temporary operator settings ie for making a new primitive, and I think maybe there was history window. Maybe also something to do with the Specials (‘w’ key) when editing.
Anybody know what I’m talking about?
thanks

Pressing F6 shows the same info as in the operator panel in the toolshelf when you are using a tool

cool! that will come in handy, thanks!
Anything else like this?