Glancing at your source, I see a lot of jQuery being used to display the photos with effects, and even some PHP generated images. I also noticed a few images around 100k in file size. Put all this together, combined with the fact there are alot of images on one page as the previous respondent pointed out, your site will not load incredibly fast.
Be sure to optimize all images, this means compress them as much as possible before losing clarity using a decent photo editing tool. Display thumbnails whenever possible, and then use the cool jQuery tools to expand the full size image with the cool effects only when selected. I can't tell what the PHP script is doing, but if its not necessary, don't use it, or cache your images.
-jim