ABOUT
Plugin Name: XHTML and Mobile YouTube
Plugin URI: http://shkspr.mobi/wordpressplugins/
Description: Allows you to simply embed YouTube videos in an XHTML 1.0 Strict compliant manner. Also allows links to Mobile YouTube for phones.
Version: 0.3
Stable tag: 0.3
Author: Terence Eden
Author URI: http://shkspr.mobi/blog/

README
This plugin allows you to easily embed YouTube videos as XHTML strict. It will automatically place XHTML valid code in your post.  
If your blog is being accessed by a mobile, it will place a link to the mobile friendly version of YouTube.

INSTALL
Either install automatically from your dashboard, or place the .php file in /wp-content/plugins/

USAGE
Within your blog, type the following
[youtube id="p5ACl4iBGd0"]

TODO:
Integration into the posting system - a button to click, paste URL, done.
Better parsing.  Allow [youtube id="http://www.youtube.com/watch?v=p5ACl4iBGd0"] etc.
Better data validation. Is that a valid YouTube video?
Better device detection?
What would you like to see?