Posting in the Magento forums has been disabled pending the implementation of a new and improved forum solution which should better serve the community.
For new questions please post at magento.stackexchange.com, the community-run support site for the Magento community. We will be providing updates on the new forum solution soon. For questions or concerns please email firstname.lastname@example.org.
Add, this product is on offer image on top of the product image?
Create transparent pngs or gifs for the circle backgrounds for discount ranges (0-20 - yellow, 20-40 red),
Use absolute positioning in categories product list to put them over the product images,
Use this formula to calculate discount percentage in template/catalog/product/list.phtml:
Im going to build this Modification and then post it lateron..
But first need my shop to be competely restyled! Im going to do an extreme makeover, which it will no longer be detectable as magento..
post my results this week or next week.