wojciechborowicz

This plugin will let you add google map as a shortcode to your website. 
It lets you create maps of two types. 
1 – Customizable Google Map, which requires API key from google. 
2 – A free embedded iframe google map.
The plugin is made to be as simple, as possible to make it easy for beginner users.
When you create a map, plugin will generate a shortcode, which you can then place on any page, post or a custom post type.

Smooth Maps

This plugin will let you add google map as a shortcode to your website.

flynsarmy

Allows the insertion of code to display an external webpage within an iframe. A WYSIWYG button is included to make adding the code easy.
See the ‘Other Notes’ tab for usage information.
<h3>Usage</h3>
The tag to insert the code is: 
 [iframe src=”http://yoururl.com” width=”100%” height=”600″]
You can use any attribute and it will work.

IFrame Shortcode

Allows the insertion of code to display an external webpage within an iframe.

Requires PHP 5.3 or later.

Smooth Maps vs IFrame Shortcode