Mailing List/Newsletter script??
 

Does anyone know of any simple scripts where I can just setup a box where a surfer can add their email to join a mailing list/newsletter?

Nothing fancy, just a simple submit box.

PHP List It isn't "simple" it is actualy quite powerful. It is easy to setup though. I've got three lists, one with over 29,000 subscribers, and phplist has made my life a lot easier. Includes bounce handling functions, email templates, batch processing so your server doesn't get hammered sending out 30000 messages at once, it'll batch them into smaller chunks.

And it is free, so you should give it a try.