Well I finally got round to actually reading the 580EX manual yesterday and think I have found some projects to keep me out of mischief over the winter.
I had a quick play with 2nd curtain sync (just a couple of quick shots in the back garden last night, so nothing I will be sending off to a magazine):
Then I started to look at high speed flash...take a look at this amazing site:
http://www.liquidsculpture.com/index.htm
and stroboscopic flash which the 580EX has a special mode for (don't know about the rest of the Speedlite range:
http://www.rit.edu/~andpph/
This is a fascinating area of photography.
Has anyone else experimented in this area?
Let's see your pics (I know EosD has an excellent shot in his gallery)