This script worked like a charm for my WordPress blog at http://www.chrisandfenna.com You can see how I put in the thumbnail into my wife's blog so anyone who visits our family site can see that I now have my own artwork blog.
Important to note though that he has an updated version of the script on his website. I couldn't get the script listed here to work on my recent wordpress. The new script works as a plugin into wordpress, and it was mostly painless to install.
Chris