Thanks for your reply "Raincoaster". I am a bit new to all this, so I may be using the wrong language.
(i) I want to develop another site featuring photos from Tropical Orchids, which do not have anything to do with Tasmanian Orchids. So the search engines would use different tags. Its fine for google search to associate this with my user name.
(ii) I wish to develop another site featuring mainly downhill bike racing photos. These will feature mostly my nephews images, so different emailing contact address. So I think you answered this question, and I will need to create a new user account.