Yes Tom
It would have to be optional (ie can choose whether it is visible or not) but would be handy for virtual products (of which there is a lot).  As I said I put the link in the description but that means they have to click the title (especially if viewing "popular products" on another page) and then click the link).

It could also have a dual role (again optional) for non virtual products in so far as being a quick checkout.  There are a high percentage of shoppers (even to the amazon.coms) who only wish to buy one product at a time.  I have on other stores a quick checkout.  So next to the "Add to Cart" link, there is a "Quick Checkout" link which just adds that item and takes you to the checkout.  Its a nice shopping experience for end users.

One link could server either purpose.  I realize the list could go on and on for extra links but 2 is the limit i would suggest and making the second one configurable for either quick checkout or trial download (or possibly custom link) would be an advantage.