I've been looking at the Galleries that I've created over the past 5 years as I transitioned from Squarespace 5 to Squarespace 7...savoring the range of topics and the improvements in my photographic skills. There were almost 300 galleries! All of them were used in blog posts but sometimes I looked at the galleries in their own space. I've created two gallery indexes (accessed via the menu at the top of each page) to make this easier; there are two indexes so far: alphabetical and by creation date (the most recent ones are at the top).
While I was working with the galleries, I gleaned the thumbnails that were the 'front image' for each of the galleries in Squarespace 5 and am displaying them below. Enjoy!