It looks like one of the nightshades. I don't remember seeing any nightshades with 5-lobed leaves, as some are in your photo, but I'm not an expert.

Are any berries ripe, and if so, what color are they? Deadly nightshade's (atropa belladonna) are black.

Some nightshades are edible, but some are deadly poison to people and/or livestock.

This is a nice clear photo of what is supposed to be deadly nightshade (I'm not sure I trust the site); note that many leaves are 3-lobed:
{{gwi:240661}}

Here's a pressed solanum dulcamara (bitter nightshade); at least one of the leaves has 5 lobes:
{{gwi:240663}}

Deadly nightshade, Atropa belledonna, looks totally different. It isn't a vine and does not have blue/purple flowers. So MTO, your suspicions are right, your first link is misnamed. Deadly nightshade is often misapplied to Solanum dulcamara, bittersweet or woody nightshade, which is what the plant in the OPs photo looks like. The leaves are variable.

This url shows Atropa belladonna, deadly nightshade. http://www.artscience.me.uk/userimages/Atropa_belladonna_flower.JPG

The link shows Solanum dulcamara, woody nightshade.

Here is a link that might be useful: {{gwi:240665}}

Thanks, flora. Apparently I was taught the wrong ID (of solanum dulcamara or a similar nightshade) as a child. It's nice to know it's a common mistake! [If I remember, I'll complain to my mother. 8-) ]

Your solanum dulcamara link doesn't work for me. Here's one I found:
http://www.kingcounty.gov/environment/animalsAndPlants/noxious-weeds/weed-identification/bittersweet-nightshade.aspx
It mentions a vining habit, but it cites red berries, so maybe what I've seen with black berries in various parts of the US all these years is yet a different nightshade....

What surprised me was the near-complete absence of any purple-flowered and multiple-lobed nightshade in the several excellent online native plant databases I usually consult when trying to identify plants I see on my property (which includes an acre of pasture and creek) or elsewhere. I'm a librarian, so I'm picky about which online sources I trust.

Well, you two certainly made short work of that! :-) Thank you so much. I read all about them. Quite interesting. Thank you so much!