Looking For Email Capture

...in the form of an invitation to a newsletter subscription for the sidebar. I am having a world of confirmation errors with G-Lock Double Opt in Manager that I can't get assistance for. And I downloaded MailPress today and can't seem to configure it right. I checked the "Showing Off" thread and I noticed http://theprivatemarket.com/, http://www.docgurley.com/ and http://www.midriffrecords.com/ seem to have what I'm looking for. http://echoesofapollo.com/subscribe/ has something interesting as well. Does anyone know what plugin(s) they are using?