functions-settings.php

<?php
class new_general_setting {
	private $field_name = false;
	private $field_label = false;
	private $field_type = false;
    function __construct($field_name, $field_label=false, $field_type='text'){
    	$this->field_name	= $field_name;
    	$this->field_label	= $field_label ? $field_label : str_replace('_',' ',$field_name);
    	$this->field_type	= $field_type;

        add_filter( 'admin_init' , array( &$this , 'register_fields' ) );
    }
    function register_fields(){
        register_setting( 'general', $this->field_name, 'esc_attr' );
        add_settings_field($this->field_name, '<label for="'.$this->field_name.'">'.__($this->field_label , $this->field_name ).'</label>' , array(&$this, 'fields_'.$this->field_type) , 'general' );
    }
    function fields_text() {
        $value = get_option( $this->field_name, '' );
        echo '<input type="text" id="'.$this->field_name.'" name="'.$this->field_name.'" value="'.$value.'" style="width:400px;" />';
    }
    function fields_textarea() {
    	$value = get_option( $this->field_name, '' );
        echo '<textarea id="'.$this->field_name.'" name="'.$this->field_name.'" style="width:400px;height:100px;">'.$value.'</textarea>';
    }
}

This is a quick way to add options to the wordpress general settings page

1. Just include the file in functions.php
2. Register settings you want to use
   $about_home_setting = new new_general_setting('about_home', 'Home page about','textarea');
   $about_home_blue_setting = new new_general_setting('about_home_blue', 'Home page blue large text','text');
3. In a theme you can get the value using: