This modification adds a textbox next to the status radio buttons in categories.php which allows you to enter a default sort order for your products (see screenshot.jpg).
The customer is still able to resort products in the product listing if they want but this mod provides a means of ensuring that your premium products are shown at the top of the listing.
To set the sort order, simply enter the number directly into the textbox.
It is easy to implement with only one column added to the products table and 8 chunks of code to copy/paste.
Also included in the miniimages.txt file is a simple mod (4 copy/pastes) to add a tiny image (your existing image scaled down, see screenshot.jpg) next to each product in categories.php
To implement this mod(s), either follow the instructions in this text file (and miniimages.txt for the image mod) or use a text compare tool such as 'beyond compare' to compare your files with those included in this zip.