Subscribe to only one category

Hi there,

I was looking for a way to allow users to subscribe to my blog, but only send them subscription updates for one of my categories. I don’t want them to have to register for an account on my blog before they can do this. I just want them to enter an email on the sidebar and click subscribe. Is there a plugin out there that can do this, or is there another way I can make it happen? The few that I saw didn’t allow me to choose the category, or it required the users to register first.

Thanks!