I've got a proposal request where they want a system like Overstock.com where the reviews are translated into star ratings that show not only on the product info page
http://www.overstock.com/Electronics...ID=prod2279689

but on the product list page
http://www.overstock.com/Electronics...s/270/cat.html

I know ZenCart does reviews. What is involved in translating those reviews into a star rating like Overstock.com has?

Thanks!

Chris