editor / log viewer etc. panels disappear: How to get them back?

I often have difficulty retrieving panels when they disappear due to some accidental keyboard or mouse action (I suppose). Sometimes, they are detached from the main window and I don't know how to put them back where they were. Dragging them sort of works, but they end up with funny sizes and don't integrate with tabs. For example, suppose the editor panel disappears. Selecting View/Editor does nothing as far as I can tell. How does one gracefully manipulate the different panels.

It appears I'm running 0.3.0dev.

Thanks