This mod is pretty easy. All it requires is a template change to add in the image location for the thumbnail API and a new cell in the table. Open up your link.tpl file for the phpLD theme you are using. Near the top of the template, right after the table and first row are opened (<table><tr>) add the following:

<td style="height: 90px; width: 120px">
<img src="http://www.artviper.net/screenshots/screener.php?url={$link.URL|escape|trim}"
alt="Thumbnail" />
</td>


That should be it! The thumbnails take a bit to be cached, but after they’re loaded once they should load quickly.