The toolbar at the bottom of all pages was designed to serve double duty.
Primarily, it's function is to act as the home for all account information. This includes credit or subscription balance, access to account preferences, site mail, payout totals for contributors and cart functionality.
Additionally, the toolbar was designed to act as a portable lightbox drawer that follows you throughout the site. Users can add, edit, share and delete lightboxes on the fly, while drag and drop functionality would allow them to very quickly populate the lightboxes right from the search results.