Display order for shop products

The order of display of the products from the database is currently based on the default of ProductId ascending. The client entered the products into the database in the order which was relevant at the time.

The client now wants to reorder the products in certain categories. This reorder is random in nature and can't see that it can be achieved by adding an order instruction to any of the database columns.

I can do this by adding an extra column for display order but this is quite a job because the database has 700 products with the largest product category having 160 products which will all need to have an order value added to the new column.

This is OK but adding subsequent products somewhere in the middle of the order looks daunting because of having to renumber the order values below the new entries.

Is there a simpler way to achieve the reordering of the display of products? If not, is there a quick way to adjust the order value for new products inserted?

if the order is not to be based on any of the existing columns, there really is not another way except to create a new column specifically for sorting the results.

this thread:
showthread.php?t=9353

has a tutorial for using ajax to accomplish setting the sort order.

Thanks, will look into it.