Most iPhone Web apps are standalone applications that live in isolation from all the others. This means that if you use a lot of these applications, you'll either have to bookmark a ton of them, or enter in all those URLs by hand. Leaflets, however, is a site that collects a bunch of small handy Web applications into a single iPhone-friendly portal. The site is very well-designed and feels a lot like an iPhone within an iPhone (even the icons look similar). Not only is there an RSS aggregator, but there's also one-tap access to iPhone-optimized content from the New York Times, Newsvine, Flickr, Upcoming, del.icio.us, and even from the Tour de France. The "leaflets" are also pretty lightweight and are designed to run fast over AT&T's EDGE network.
You do have to sign up to use Leaflets, and provide a login and password. But once you do so, it'll remember your login information for the applications within the collection. We especially liked the Flickr app, which lets us view comments, contacts photos, and so forth. Once you're done using an application, just hit the "Home" button on the upper left corner, and you'll be brought back to the Leaflets home page. Hopefully as time goes on, Leaflets will add more applications to its portal. So far, I'm really liking it, since I use Flickr and Upcoming all the time. We definitely recommend checking it out.