This is a simple piece of functionality that takes advantage of the usermanager tag library. The Logged in User id can be retrieved using the usermanager:getloginuser tag and you can out put this to a var using the attribute varname="". The Logged in User name can be retrieved just as easily using the usermanager:getloginusername and similarly output to a var.
To get the current username and id use the following
<usermanager:getloginuser varname="currentUserIdString" /> <usermanager:getloginusername varname="currentUserName" />
