would it be possible to add some redirection magic to .htaccess to enable the use of the free cdn at http://www.coralcdn.org/ ?

I've tried using details from this blog post :-

http://www.reaper-x.com/2009/10/02/how-to-use-coralcdn-to-save-your-bandwidth-problem-server-resources/

but not got it working.

I don't know that but if it involves hosting albums on another server no: http://www.zenphoto.org/2009/03/troubleshooting-zenphoto/#17

There's no reason it wouldn't be possible. CoralCDN works entirely off of DNS redirection, so it should work with any website.

However, I couldn't tell you how to make it work with your own website. You'll have to figure that out on your own.

Got it working with :-
`

Header append X-Coral-Control "redirect-home"

RewriteCond %{HTTP_USER_AGENT} !^CoralWebPrx

RewriteCond %{QUERY_STRING} !(^|&)coral-no-serve$

RewriteRule ^cache/(.*)$ http://gallery.weloveit.info.nyud.net/cache/$1 [R,L]

`
Also needed to make sure I had the headers module activated and running.