Google Plusone(+1) Button plugin by webgig, Pravash Chamling Rai displays the google +1 button in different styles and positions.
Features:
Display Google +1 button in the posts, pages, single posts or everywhere.
Display Google +1 button above the post [‘Top’], below the post [‘Buttom’], both above and below [‘Both’], or floating left side of post [‘Left’].
Display Google +1 button in four different sizes (Standard, small, medium and Tall)
Display Google +1 button using Template Tag or Shortcode [twg_gpo_button] at any desired position.
Preview in the settings page with a dummy post.
Plugin homepage: http://thewebgig.com/google-plusone-button-wordpress-plugin/
Download; http://wordpress.org/extend/plugins/googleplusone-button/