Hi Ken!
Wow, lotsa questions!
I use a pop up window on my site, and I am also participating (as some other folks are here) with Subscription Rocket which uses a Pop Under box. Subscription Rocket has been very effective for me.
I also have articles published in many places online with my resource box including a clickable "mailto:" subscribe link so if a person is reading along in his/her email box and at the end of the article thinks what I offered was valuable, he/she can click and instantly subscribe. Really sweet and simple.
Another quick thing to do is to contact some of your contacts who are also publishers and arrange a few ad swaps. The best kind are the ones where your contact actually recommends whatever it is you are promoting. If its your ezine, ask your contact to give a heartfelt recommendation. Works a lot better than just the standard ad from my experience. I think I have seen these referred to as "advertorials".
In case you are not using Subscription Rocket yet, it is fairly simple to sign up. I have created a link for anyone to use here
Happy List Building!
With Passion and Purpose,
Julie Jordan Scott
Dare to Discover Your Passion, Decide to Live Your Destiny