I downloaded the plugin anyway and simply activated the sample plugins (delicious and Google) they provided (which worked), and went from there. Like Otto42 said, the widget_init hook resolved everything.
The biggest issue for me was that the actual widget plugin readme that automatic has online mentions loading plugins first, but didn’t go far enough for me to know about that hook. And the WordPress documentation doesn’t have that hook listed either (that I can find), and for that matter, doesn’t even have the widget functions from widgets.php listed in the functions reference. Maybe I need to go try to put some documentation in there on some of these, I’ve been meaning to do it for the mail function anyway.
