[Toadling]

pendolino, this thread is pretty old and some of these posts no longer apply. For example, OF *does* warn you when deleting an "empty" folder which contains projects that are hidden in the current view.

There's also a built-in perspective to show everything. Take a look at Perspectives -> All Items.

But I agree that an option to search all or only the current filtered results would be a nice addition, especially if it was built around the toolbar search field: perhaps a pulldown arrow in the search field like iTunes has that has various scope options or even an extra bar that appears at the top of the content area like Apple Mail does when a search is active. I believe the Omni Group has stated that something along these lines is planned for a future release.