HotorNot.com, the infamous social rating site that made it through the dot-com bust has a new, and free iPhone app out. As you'd expect it lets you pass judgment on others by scoring them anywhere from 1 to 10. It also lets you tap into its "Meet Me" network where you can get in touch with other registered users to set up dates.
The software makes use of a few of the iPhone's hardware features, including GPS. This lets you hit a button to narrow down where the results are coming from. This works both for the meeting portion of the site as well as the rating. Likewise, registered users can take snapshots of themselves using the phone's camera and post it straight to the site.
Many of the application's features cannot be used without registration. For instance, you cannot bookmark favorite users, send them virtual gifts, or upload pictures without a log-in ID. My guess is that most people will download it if only to start viewing and rating photos, then feel the need to register to continue using the app to its full potential. Keeping many of the more interesting features under wraps until users register seems like the smart way to go.