The new version of the WordPress Web Form plugin retains all of the old features. But upon updating, or installation of the new version, users can activate and select the list that subscribers will be subscribed to. Now when a reader leaves a comment, they have the option of checking a box to subscribe to the list that’s been setup. A pane will also be added to your dashboard to track your subscription numbers.
WordPress Web Form Screenshot Gallery
Do you use AWeber to collect emails, or do you even manage a mailing list? It would seem that this sort of easy signup process would increase mailing list numbers, but what do you think?