WP Sidebar Login is a WordPress plugin by Pankaj Jha that has both a widget and a template tag to allow you to have a login form in the sidebar of your wordpress powered blog. It lets users login, and then redirects them back to the page they logged in from rather than the backend, it also shows error messages. This plugin adds the capability of placing a login widget in the sidebar with smooth AJAX login effects.
Works on all modern browsers.
Work With all the cache plugins.
Shortcode and template tags available just add to your page.
AJAX Login without refreshing your screen.
Redirect back to the same page or as per the configuration
Plugin homepage: http://onlinewebapplication.com/2012/07/wp-sidebar-login.html#.T_qDUo6xp6o