Dave Doolin

Aweber Super Simple is a plugin that will subscribe a user whenever 
he/she registers to your blog.
The AWeber Super Simple options page allows you to configure the plugin to: 
* Choose whether or not to display the optin checkbox. Users may register if optin isn’t shown, and will not added to autoresponder. 
* Choose a checked or unchecked default status for the optin checkbox on registration. 
* Provide a custom optin greeting message for visitors
This code base is at least once, possibly 3, 3 or more times removed from what was the original 
code base. Wherever or whenever the ultimate source, the base code is old in WordPress years. 
Current effort is to bring everything up to 2.8 coding standards before attempting any extensions.
<h3>Support</h3>
Initial functionality will be supported on a time-available basis.
Installation, configuration and further programming support may be 
available on a contract basis. Contact author with request.

Aweber Super Simple

AWeber Super Simple allows you to subscribe users to an AWeber autoresponder when they register on your blog. NOTE: ALPHA VERSION.  Be careful.

GKauten

Integrates the AWeber contact registration script into your WordPress registration process. 
Users are seamlessly added to your AWeber account during registration on your site, either 
by request or silently. If you do not yet have an AWeber account, you will need to 
visit their website (http://www.aweber.com) and sign up for one.
If you find this plugin useful, please donate. Donations help pay for my AWeber account which 
allows me to continue supporting and improving this plugin as WordPress and Aweber continue 
to evolve on their respective paths.
Special thanks to Guru Consulting Services, Inc. (http://www.gurucs.com) for their 
original platform on which some of these functions derive.

AWeber Registration Integration

Integrates the AWeber contact registration script into your WordPress user registration process.

Aweber Super Simple vs AWeber Registration Integration