modal dialogs

Hi,
I'm not sure if it this count as a keyhole but at least it obstruct the view of the big, wide, wonderful world for a certain time. I speak from dialogs called "Modal dialogs" (This term was used in Borlands C++ builder guide). This dialogs appear often together with a fixed size window and block the application for a specific task. E.g. if I fetch emails from my mailbox to my PC I'm not allowed to write a new email. A window which informs about the status of download process prevents me from typing a new email instead.
>From a programmer point of view "modal dialogs" simplify work but not always it is necessary.