http://drupal.thedonkeysanctuary.org.uk/
I joined the Donkey Sanctuary in Devon in October 2007 and shortly after that I heard about Drupal and haven't looked back. It's a brilliant CMS. The open-source community are a great support. Whenever I've been stuck with how to do something, whether it be something simple that the old brain cells forget, within minutes someone's popped a reply to a posting and I'm off on my way again.
I had the basic structure of the Drupal website in place within months replacing parts of it as I learnt things along the way, such as views. A whole new world once I understood them :-)
Only problem I have is adding images into the blocks. Probably a theme issue rather than anything else. I'm using the Amadou theme and the image behaves unless the browser happens to be Microsoft IE then it floats off somewhere !!!
Most of the time when you have an idea, just look in the list of modules and there's always something that fits that idea.
The Sanctuary prides itself on ensuring donations received go directly where needed - helping the donkeys in the UK and with our projects overseas. Administration costs are somewhere around 8.2p in the £.
By using Drupal, we haven't had to spend any money on commercial packages to build a wonderful our website keeping admin costs down.
It's been fun learning too :-)