Scott Taylor

Like Buttons makes your site instantly share-able. The plugin adds <code><meta></code> tags to your pages’ HTML <code><head></code> which will pull the proper content from your site when someone shares one of your site’s URLs on Facebook. Using some simple Theme functions, you can add Like buttons to posts / pages / custom post types AND a Like button for your blog / website
<pre><code>// in the Loop - for posts / pages / custom post types
the_like_button()

// a Like button for your blog / website, put it anywhere!
the_blog_like_button()

// use this if you don't want to register your app
the_like_iframe()
</code></pre>
Read More: http://scottctaylor.wordpress.com/2011/01/04/new-plugin-like-buttons/

Like Buttons

Adds Open Graph  tags to your posts/pages/etc, adds a Facebook Like button to posts using simple Theme functions. Requires a Facebook Application ID ( …

LaClave

The MasDetalles share plugin to help people share, bookmark, and email your posts and pages using Masdetalles share. New: MasDetalles share.
MasDetalles Share le permite compartir sus enlaces en el marcador social Masdetalles.do desde su blog, email, tienda virtual, y cualquier pagina web.

Masdetalles Share

Help people share, bookmark, and email your posts, pages, your favorite links through MasDetalles.do

Like Buttons vs Masdetalles Share