A:
1) Visit their profile page
Above any slideshow, you will find the username of the creator. When you click on this username, you can visit the profile page to see all the public slideshows of this user. For example, username cappy's profile page is at http://photopeach.com/user/cappy.
2) Follow the creator
When you are logged in, you will see a "Follow" button above every creator's slideshow. By clicking the "Follow" button, whenever the creator publishes a new public slideshow it will appear on your home page automatically.
In any case, you can see only the public slideshows of any creator -- you will not be able to see any unlisted or invitation-required slideshows.
