Note: Following concerns vanilla Plone only. If you have customized membership behavior it doesn’t necessarily work.
Member profile properties (title, address, biography, etc.) are stored in portal_membership tool.
Available fields can be found in ZMI -> portal_membership -> Properties .
ToolbarViewlet has some sample code how to retrieve these properties.
In template you can do something along the lines:
<tal:with-fullname define="membership context/portal_membership;info python:membership.getMemberInfo(user.getId()); fullname info/fullname">
You are are <span class="name" tal:content="fullname" />
</tal:with-fullname>
Note that this code won’t work for anonymous users.