Wild Grapes?

We have what looks like a grape vine growing on the fence that runs along the road.  The other day I noticed it had small light purple fruit on it.  Here's a picture of the fruit.

(Click on the picture to make it bigger)

As you can see, these don't look anywhere near like the grapes you get in the supermarket.  But, I got to wondering if you could eat them.

One web site I found that talked about wild grapes was by Fairfax County Public Schools in Virginia  http://www.fcps.edu/islandcreekes/ecology/wild_grape.htm

All this says about eating them is that wild grapes are "not often eaten by people".  But, apparently, a lot of animals eat them and use them for shelter.  In fact, it says that "there are few plants which feed so many different animals".  I can see how these vines might become a problem in some situations.  But, it sounds to me like the benefits to wildlife far outweigh their liabilities.  So, I'm all for keeping them and letting them grow on our fence!