Email Subscription script

[Sererena]

Hi there!  This probably has nothing to do with cmsms, but I figured I'd ask for any suggestions since you guys seem very experienced with creating websites and all that.

Basically I'm looking for something that would let me gather email addresses by a form I could slap anywhere on my site (the form just has one field: email address; so that it will be convenient for surfers) and that would put all the emails in a text file I could download via ftp....  right now I'm using an email form thing to do it, but that doesn't work for everyone.

This is probably really simple, but I'm no programmer and don't know where to begin.