I wrote a webapp that deals with web security, specifically, creating an API wrapper around a web service to handle Two-Factor Authentication for websites that want (and likely need) the added security, but don't want to deal with it themselves. Basically, instead of just having a username/password, this system lets you have a login page with a username/password AND a temporary N-length alphanumeric one-time-use password that's SMS'ed to your cell phone and good for X minutes. All you need to do is add 2 method calls to the API.
In any case, I think it's a much needed product for countless websites, but I want to be sure I have all the wants/needs of future customers covered before I start pushing it. (Yes, there's companies that do this already, but they're MUCH more expensive, and require you to install a LOT of their software on your server).
I have a full list of all the features on the "sell" page, but I'm sure I'm missing some things that potential customers would want. So, please, feel free to let me know what I'm missing, and what you'd want from a service like this.
http://nxtpass.com