Hello!
I've that on Walking Papers we can "print" a map with 'bing aerial imagery', you scan it and can edit directly with osm/potlatch. Is it legal? I didn't find any legal information about these aerial images.
Example: http://walking-papers.org/print.php?id=rx9v5vqb this is in preparation for Rencontre Vaudoise du 5.3.11 : http://wiki.openstreetmap.org/wiki/RencontreVaudoise20110305
Best regards
Stéphane