These are RSS feeds --- you can subscribe to them (normaly your browser will handle them). There is alot of them thrown around so, don't assume one is enough for everything.
If you like, love, adore a photograph, click on this (on the page the photograph is viewed). You can see all the photographs you love by going here.
The background switch allows you to: switch to black. In some cases some photographs look better on a black/dark background framing.
Wherever you see this plus-sign below a person's avatar means you can add that person as one of your contacts
This icon will allow you to share any photograph thought other social websites (muti, facebook, digg, technorati, stumble upon, twitter and delicious.)
I/We not sure about Facebook --- their terms are not as scary as they used to be.
This allows you to view a larger (or smaller version [the icon will have a 'minus' when already viewing a larger version) of a photograph.
We have removed the 'preview' functionality and added the slideshow – whereever you see this icon, you can view a slideshow of those photographs.