@ David
This inspired me to toss together a free extension for Connections named, very creatively, Login. I’ll post it to the .org plugin repository as soon as I can, but if you are familiar with Github, you can download it now from here:
https://github.com/Connections-Business-Directory/Login
If you do, to configure it you have two options.
One, on the Connections : Settings admin page under the Display tab, you can enable it as a single entry contact block.
Two, this extension adds a new widget which can be placed in the theme’s sidebar. It will only display on the single entry page if the user is not logged in.
If I have not asked and if you have a moment, I would truly appreciate a review as they really do make a difference. Many thanks in advance!
http://wordpress.org/support/view/plugin-reviews/connections