select_media.html

<h3>My Picture (1)</h3>
<input type="text" id="my_media_1" name="my_media_1" value="" />
<a class="media-upload" href="JavaScript:void(0);" rel="my_media_1">Select File</a>

<h3>My Picture (2)</h3>
<input type="text" id="my_media_2" name="my_media_2" value="" />
<a class="media-upload" href="JavaScript:void(0);" rel="my_media_2">Select File</a>

select_media.js

jQuery('document').ready(function(){
    jQuery('.media-upload').each(function(){
        var rel = jQuery(this).attr("rel");
        jQuery(this).click(function(){
            window.send_to_editor = function(html) {
                imgurl = jQuery('img', html).attr('src');
                jQuery('#'+rel).val(imgurl);
                tb_remove();
            }   
            formfield = jQuery('#'+rel).attr('name');
            tb_show(null, 'media-upload.php?post_id=0&type=image&TB_iframe=true');
            return false;
        }); 
    }); 
});

select_media.php

<?php

add_action('admin_print_scripts-'.$hook_suffix, 'my_admin_scripts');
add_action('admin_print_styles-'.$hook_suffix, 'my_admin_styles');

function my_admin_styles() {
    wp_enqueue_style('thickbox');
}

function my_admin_scripts() {
    wp_enqueue_script('media-upload');
    wp_enqueue_script('thickbox');
    wp_enqueue_script('jquery');
}

?>