I was so sad when instapaper removed this already built-in feature. Not sad enough to re-write it mind you.

awesome! you can consolidate about 90% of the current push apps in the iPhone store with this one. (in theory at least)

"A simple, open, web-hook-based pubsub protocol & open source reference implementation."

"Turn your favorite feeds into a personal magazine"

On the fence about this right now... but feed consumers have to do something. I was wrestling with similar issues when spec'ing out a system to collect feeds (yes, millions per hour) for an internal linguistics project... in the current environment HTTP If-Modified-Since just isn't enough.

"Plagger is a pluggable RSS/Atom feed aggregator written in Perl. Everything is implemented as a small plugin and you can mash them up together to build a new application to handle RSS/Atom feeds."

"A class to wrap Mark Pilgrim's Universal Feed Parser module so that parameters can be used to cache the feed results locally instead of fetching the feed every time it is requested. Uses both etag and modified times for caching. The cache is parameterize

"Webpage-to-RSS Pipe generates RSS from any webpage which doesn't have native syndication. It utilizes a data mining service called Feedity ( www.feedity.com ) to dynamically build the RSS, and then only return unique items."