I sell items that I'd like to 'sold out' items to remain visible in my shop but not in the actual products for sale section.

For example, if you look at http://www.skateboardstickers.co.uk/...ndex&cPath=1_9 I'd like the top 2 to automatically move to an 'archive' or 'sold out' category so people don't have to scroll through the sold out items.

I understand this would be possible by hand by copying the products to a 'archive' or 'sold out' but this would be time consuming for when products sell or if I restock. Is there an automatic way for products to automatically move or does anyone have any tips to make this a less time consuming process.