I'd first like to thank you for producing a plugin that does a great job and one that I have already used multiple times in multiple ways. I'd like to offer a couple of feature suggestions that you might consider.
1) First, an administrative option to export the stored names and addresses to a comma-delimited file would be nice. I tried to export the connections table from the mysql database but the output file had lots of additional system information that was unnecessary for the purpose I had in mind.
2) Second, I was able to modify the existing code in the connections.php file (function _connections_list($atts, $content=null) to be specific) to allow me to publish a heading for each alphabetical letter group as well as to replicate the alphaindex at the top of each letter group to aid in navigating what could be a fairly long membership list. I really like the way it turned out and you can see the results at http://www.tipmasters.biz/index.php/directory/ if you'd like to see how this looks. I think this would be a nice option to have as it doesn't require the user to go back to the top of the page in order to jump to another alpha letter group.
So far I've been very pleased with the results I've been getting with the plugin and it is very easy to read your code and figure out what is going on. As time permits and needs change I'll probably dig even deeper into the code, but for now these are the two suggestions I've been able to come up with.
I just did the latest update and it was very easy for me to migrate the changes I had made previously to the new version. Thanks for creating such a useful tool!