Finnish photographer Kari Kuukka has posted an interesting account (in English) of how he shot a 360-degree panorama image
of Helsinki from a helicopter. The shot itself is not stunning, but Kuukka's blog post about the assignment details the many unusual obstacles that had to be overcome to get the photograph. The post does not say how he erased the helicopter itself from the shot, however.
The panorama image is in HTML5 format, and we successfully viewed it using Safari 5.1 on a Mac. Kuukka says it also looks good on an Apple iPad2; how it renders in other browsers or devices may vary. When viewing the image, click the "next" buttons to see the photo with and without the helicopter, and to read Kuuka's blog post.