Some time ago, there was a question on the Drupal forums about wrapping content from another site to your site.

Here is a basic PHP code snippet that would do just that. You may need to fiddle with the HTML to make the paths absolute to the site that you are wrapping.

If you have improvements, please let me know. 

Also, please do not use this to leech content from other sites, and obey their copyright rules. 

Method 1: Using fopen on a URL 

$url = "http://example.com";

$handle = @fopen ( $url, "r" );
if ( $handle ) {
 while ( true ) {
   $data = fgets ( $handle, 4096 );
   print $data;

   if ( true == feof( $handle ) ) {
       break;
       }
 }

 fclose ( $handle );
}
else {
 $result .= t("Could not contact host: ") . $url;
}

Method 2: Using fopen on a URL - more concise way

After writing the above, Drupal hacker par excellance, Karoly Negyesi (a.k.a. chx), found  a much more elegant and simple solution:

$url = "http://example.com/page.html";
print file_get_contents($url); 

This is much less code for sure. 

Method 3: Using IFRAMEs

You can use an IFRAMEs to wrap content from another site, or another application on your site.

To do this, all you need is to paste the following HTML snippet in the block or the node you want. You will have to experiment with the height and width until you get the size that works best for the site you are wrapping.

<iframe
src="http://www.example.com"                    
Frameborder=0
height="600"
width="640">
</iframe>