Can I restrict a download to free with purchase?

I have a couple of download products set up and I am wondering if I can restrict the downloads to be "free with purchase". I don't want to set them up with a price and then coupon or something like that though (don't want to sell the item individually)

So right now, the download product shows up in the catalog with a price of 0 and will let you add it to the cart and go through checkout with no payment. Is there any way to get the cart to stop the process if there are no other non zero items int the cart? Or just someway to workaround that I haven't been able to think of?

You would need to make a special function to control these being in the cart and assure that there is a real product in the cart before checkout is allowed ...

Cheryl - am wondering if you successfullymanaged to set this up.

I was going to add a downloadable attribute (I'm guessing we're attempting the same thing - free pattern with purchase of yarn) - but unfortunately the stock by attrib mod (well, the way I have it hacked anyhow) does not allow me to have multiple attributes.

Curious to hear :)

Never did get it to work that way. I finally just listed the product with a price of .01 and put "free with purchase" in the description.