I'm interested to hear this too. On the one hand, I went with a minimal 'give me your email' address form that I could make as attractive as possible without putting too much effort into it -- on the other hand, now that it's out there, I feel like I should have my value prop, an intro, a _reason_ to leave your email address.

It's very difficult to leave it as a static page when I know that it can be better, but I'm fighting the urge to keep tweaking the prelaunch page and instead, keep working on product. I do have a deadline to meet, after all.

Here's what I went with: http://plumrss.com/