I feel like organizing things. This will surely pass, so I'm making the most of it!
The only way I can find them is by looking under "you" in my account and going to "your galleries", or by coming across a photo already added to a gallery. BTW, if your photo happens to be added to a gallery somewhere on flickr, when you are looking at the photo you will see something like this in the middle of the right side of the page:
Originally, I thought the galleries might show along the right side like the "sets" do in my photostream. Which you can get to them by clicking on "more sets" at the bottom of the page, and then selecting the galleries tab, but they don't seem to be prominently displayed anywhere.
So my intentions are good, and my intuition tells me there is a good reason to do this, but I'm not quite sure how to make the best use of the galleries! Maybe they are just to make me feel organized for a brief moment in time.