I'm always hunting for simple tweaks to maximize my searching capabilities.

Here's new one: Admin> Products>Search> "Product ID"
Helps you find a product by Product ID number.

Very simple:

/admin/categories.php

Around line 3519 find

WHERE p.products_id = pd.products_id
and pd.language_id = " . (int)$languages_id . "
and p.products_id = p2c.products_id
and (pd.products_name like '%" . tep_db_input($search) . "%' or
p.products_model like '%" . tep_db_input($search) . "%')
ORDER BY p.sort_order, pd.products_name");

line after:
and (pd.products_name like '%" . tep_db_input($search) . "%' or

add:
p.products_id like '%" . tep_db_input($search) . "%' or

In between first line and next lines:
p.products_model like '%" . tep_db_input($search) . "%')
ORDER BY p.sort_order, pd.products_name");


Finished it looks like this:

WHERE p.products_id = pd.products_id
and pd.language_id = " . (int)$languages_id . "
and p.products_id = p2c.products_id
and (pd.products_name like '%" . tep_db_input($search) . "%' or
p.products_id like '%" . tep_db_input($search) . "%' or
p.products_model like '%" . tep_db_input($search) . "%')
ORDER BY p.sort_order, pd.products_name");