I didn't watch any of the Royal Wedding, but find this photo fascinating.

This high-definition, 1.15-gigapixel picture, is a composite of 189 images. The full picture measures 81,471 pixels by 14,154 pixels. The field of view covers 200 degrees.

http://www.bbc.co.uk/news/uk-13200114

That would be touch to put together (besides just processor time) because you know those people were moving in between shots. You would have to go in and do all of the borders by hand. I've done a few of these merged photos from a large group of shots, to make huge prints from. It takes forever, especially once you notice while stitching shot 37 or so that the sky has been getting about 0.5% lighter in each consecutive merge across the image / Making them has taught me what NOT to do, though, so the next time I feel inclined, I should be able to get a mistake free one.

Or maybe just find some color film for the old 11x14 camera instead...

A little research found this from the photographer -

It's a composite of 189 photos shot in 7 rows and 27 columns over a 1 hr period that includes dignataries going out, national anthems and the procession itself. I used images that most looked like the crowd was looking in the right direction and blended them.

LOTS of post pro, masking and cloning.

Nikon D700, D300 and two VR 70-200mm lenses (one on a programmed head and one to shoot detail by hand).

Henry Stuart
Spherical Images Ltd