Cumulonimbus

It's true: always take your camera. This one was taken with my Canon Ixus 870IS. Had to do a panorama to get the whole thundercloud in. Unfortunately I tilted the camera a bit while taking the photo - I was perching precariously on the roof of a bicycle stand at the EPFL - hence the distortion at the bottom.

The colours were brilliant, so brilliant in fact: I desaturated the photo a bit in Picasa, it looked too kitschy.

Addendum 7/11/2009 1105h:

Thanks Armin for telling me about Panoramastudio, a much better stitching software than Photostitch. It has built-in distortion correction, and came up with this:

This time I left the colours as they were, so you can see it in all it's kitschy glory. Makes you wonder why there is no unicorn...