Outlines of Bing images

I know from the polish community: it is helpul to generate a kind of overwiev:
Which aras have Bing coverage.

How does it work?
Example see:

http://www.openstreetmap.org/?relation=1583230

I tryed to create a outline relation.

http://www.openstreetmap.org/?relation=2108604

Everybody can now improve this relation!