My website needed a block like this and I really like all of the options it has- especially showing the User's Profiā¦
w2f
This easy to use and configure block lets you place a Login Block on any page. Once a user has logged in the same block can display their User Information, including Avatars, Badges, User Attributes and more
Documentation at: http://webli.us/add-ons/login-user-info