OpenAppMkt aims to be an App Store for HTML5 web apps. Apple considers HTML5 web apps to be the second major iOS platform, and the unregulated one where you can find everything from Google Voice to porn. OpenAppMkt lists them, features them, and includes ratings. Well, except for porn; they don't include that. Google's Voice web app currently has 4 stars though.
HTML5 apps can apps initially open in Safari but with a tap of the + button and a Add to Home Screen, they can cache locally and work, more or less, like native apps. They don't perform quite as well and can't do quite as much -- yet -- but they work surprisingly well for an ever increasing ranges of things.
Unlike Apple's web app gallery, there's even an iPhone version of OpenAppMkt you can add to your home screen. If you give it a try, let us know what you think.