WordPress.org

It has the following features:

• This plugin provides a widget with 2 links (Login, Register) for the anonymous user.
• When the user clicks on Login or register the requested form appears in a nice ajax popup.
• The login and register forms can validate using ajax and not redirect on error.
• On success the plugin redirects to the welcome page.
• When user is logged in, the widget provides a Welcome !username message and a link to the user page and a logout link.
• This plugin integrates the thickbox plugin with the Ajax and provides a simple, easy to use and cool login and register widget.