This is an object-oriented sample Wordpress plugin. Blog Post: http://www.kernelcurry.com/blog/object-oriented-wordpress-plugin

hello_dolly_oop.php

<?php
/**
 * @package Hello_Dolly_OOP
 * @version 0.1
 */
/*
Plugin Name: Hello Dolly OOP
Plugin URI: http://kernelcurry.com/blog/object-oriented-wordpress-plugin
Description: This plugin is an object oriented version of Matt Mullenweg's Hello Dolly plugin.
Version: 0.1
Author: Michael Curry
Author URI: http://kernelcurry.com
*/

Class HelloDolly
{
	public function __construct()
	{
		add_action( 'admin_head', array( $this, 'dolly_css' ) );
		add_action( 'admin_notices', array( $this, 'hello_dolly' ) );
	}

	public function hello_dolly()
	{
		$chosen = $this->hello_dolly_get_lyric();
		echo "<p id='dolly'>$chosen</p>";
	}

	public  function dolly_css()
	{
		$x = ( is_rtl() ? 'left' : 'right');

		echo "
			<style type='text/css'>
			#dolly {
				float: ".$x.";
				padding-".$x.": 15px;
				padding-top: 5px;
				margin: 0;
				font-size: 11px;
			}
			</style>
		";
	}

	public function hello_dolly_get_lyric()
	{
		$lyrics = array(
			"Hello, Dolly",
			"Well, hello, Dolly",
			"It's so nice to have you back where you belong",
			"You're lookin' swell, Dolly",
			"I can tell, Dolly",
			"You're still glowin', you're still crowin'",
			"You're still goin' strong",
			"We feel the room swayin'",
			"While the band's playin'",
			"One of your old favourite songs from way back when",
			"So, take her wrap, fellas",
			"Find her an empty lap, fellas",
			"Dolly'll never go away again",
			"Hello, Dolly",
			"Well, hello, Dolly",
			"It's so nice to have you back where you belong",
			"You're lookin' swell, Dolly",
			"I can tell, Dolly",
			"You're still glowin', you're still crowin'",
			"You're still goin' strong",
			"We feel the room swayin'",
			"While the band's playin'",
			"One of your old favourite songs from way back when",
			"Golly, gee, fellas",
			"Find her a vacant knee, fellas",
			"Dolly'll never go away",
			"Dolly'll never go away",
			"Dolly'll never go away again"
		);

		return wptexturize( $lyrics[ mt_rand( 0, count( $lyrics ) - 1 ) ] );
	}

} // End Class

$hello_dolly_oop = new HelloDolly;

Hello, Thanks for sharing a simplified OOP plugin framework for wordpress.. It would be great if you add a simple option page (settings page) for this framework..

Thanks once again..
Cheers..