This is great plugin on work, but user interface is very poor.

Although it worked with Yahoo, AOL and a few providers, it didn't work for the ones which I need. MySpace and Facebook. It would login and load my contacts accurately, however after I send my message, I would receive an error stating the form fields weren't filled out. This happens specifically with MySpace and Facebook.

I hae tried both parainvite and open inviter. Open inviter only gave me one page of like 6 config options. I could not see anything that explained how to do plug ins.

It didn't really work. I added a menu item for it and when I clicked it is went to a page with fields, but there was nothing there.

This is an excellent tool, of you are looking for free email marketing of your website :). I wish i could have had the icons of all the service providers displayed in the body as it shows in demo.

It does the job.
Maybe you will need to do some css tweaks to integrate it properly in your site, but it's good and free!

Maybe can be used as a starting point for a more complex extension.