LeapTag is an RSS reader with a twist: Instead of letting you easily subscribe to feeds and then showing you what's new in those feeds, you subscribe to tags and topics, and it finds items from the blogosphere that it thinks you'll like. As you tell the system how much you like the items, it improves its selections for you.
TechCrunch compares it to StumbleUpon, which is apt. It does help you find items that you'll find interesting on sites you may not know about.
But once you find a new site you like, you have to go elsewhere to subscribe to the site's feed. That is one of LeapTag's greatest faults. It reads feeds, but it's not a feed reader. You cannot manually add a feed to it. Because it's not a feed reader, LeapTag adds a step to, rather than simplifies, the daily process of reading blogs--assuming you still want to scan your main blogs for all their new items, not just the ones that an algorithm thinks you might like.
And this secondary reader is going to take a fair bit of time to learn how to use, set up, and manage.
LeapTag's other fault is its footprint on your system. It operates as a browser plug-in and relies on a Windows (or Mac) executable file as well. It puts new items in your main browser toolbar and gives you a new sidebar. It's a pretty heavy installation, as opposed to a fully browser-based reader like Google's, the simple toolbar of StumbleUpon, or just the bookmarklet from Del.icio.us. LeapTag CEO Cuneyt Ozveren told me the company put all its functionality on the desktop to ensure privacy and security of LeapTag's data. But for a tool like this, which users need to be convinced to use, I think a lighter weight, browser-based solution would make more sense.
Still, there's something really great about LeapTag. It will help you find more stories and sites to read, and it will get better for you over time. Just be prepared to put the work, and time, into it.
Leaptag will be demonstrated at Web 2.0 Expo.