Why not just email him and ask?
His Contact page has two email addresses for you to choose from.
EDIT – And if he tells you, be sure to post the answer here!
I emailed him and asked about a week ago and haven’t received a reply. Since posting this I’ve been able to dig around a bit more and realized that he is using Simple PHP Gallery v1.1
I spent a good deal of time analyzing the output of his site to see how he integrated it into wordpress. I downloaded his CSS files and have nearly recreated all of the changes he made.
I really like this Simple PHP Gallery program. It’s hard to find the original to download and there is a much more complex enhanced Simple PHP Gallery out there based on the same code. I don’t like it though. SPG is as simple to use as Lazy Gallery but is much easier to integrate into various themes.
Contact me if you are interested in getting a similar setup integrated into other themes than beeblebrox. I can set you up! 🙂
http://walkingtowel.org