Yes, the Image Gallery is a pretty basic module, and is a single gallery per instance.
You might also try the Image Gallery (Simple Folder Version). It mirrors a folder tree of images, which could give the appearance of multiple galleries within an instance, depending on how the images are arranged in the folder tree. There's also the Flickr gallery module, which I haven't tried myself, but may be more what you are looking for.
I hope that helps,
Jamie