JR Tashjian

This plugin was created to retrieve and cache an RSS feed for use in a template.
What you do is pass the url to the feed you would like returned and the number of minutes you would like the feed cached for. The 
plugin will cache the RSS xml and return the feed as an object which you can loop through and output however you please.
New As Of Version 1.5: 
– Fixed a typo that caused the feed to be retrieved and cached every time. Credit: Binny V A (http://www.bin-co.com/blog/) – Thanks man!
<h3>General Usage</h3>
fetch_feed_cache() is the only function you will be using with this plugin. fetch_feed_cache() accepts 2 parameters.
<ol>
<li>(string) $url – This is the URL to the feed you would like to parse</li>
<li>(int) $cache_min – This is the amount of time in minutes you would like the feed cached for.</li>
</ol>
Here is an example of the plugin being used in a template:
<pre><code><?php $xml = fetch_feed_cache("http://jrtashjian.com/feed/", 60); ?>
<h3><?=$xml->channel->title?></h3>
<ul>
 <?php if( ! empty($xml)) : ?>
 <?php foreach($xml->channel->item as $item) : ?>
 <li><a href="<?=$item->link?>"><?=$item->title?></a></li>
 <?php endforeach; ?>
 <?php else : ?>
 Delicious doesn't seem to be working at the moment...
 <?php endif; ?>
</ul>
</code></pre>
Remeber, every feed could be different. If you need to see the structure of the object returned just use print_r(). 
Example: <code><?php print_r(fetch_feed_cache("http://jrtashjian.com/feed/", 25)); ?></code>

Fetch Feed

Fetches an RSS feed and returns RSS as array

padraic

Implements <a href="http://pubsubhubbub.googlecode.com/svn/trunk/pubsubhubbub-core-0.1.html" title="the PubSubHubbub protocol" rel="nofollow ugc">the Pubsubhubbub protocol</a> based on the current PubSubHubbub Core 0.1 Specification and any changes since its publication. <a href="http://code.google.com/p/pubsubhubbub/" title="PubSubHubbub" rel="nofollow ugc">PubSubHubbub</a> is an open, simple web-scale pubsub (publish/subscribe) protocol capable of notifying one or more Hub Servers (e.g. the reference open source <a href="http://pubsubhubbub.appspot.com/" title="implementation on Google App Engine" rel="nofollow ugc">implementation on Google App Engine</a>) of your blog updates so they may be forwarded to any of your feed’s Pubsubhubbub enabled Subscribers as quickly as possible.
Any Pubsubhubbub enabled Subscriber can then receive an almost immediate update from any of your Hubs containing the actual update for immediate use. Subscribers know what Hubs to use when subscribing to your RSS 0.92, RDF/RSS 1.0, RSS 2.0, or Atom 1.0 feeds since this plugin will insert one or more links to your configured Hubs into these feeds.
WP Pubsubhubbub has the following features:
<ul>
<li>Supports multiple Hubs configured from the settings page</li>
<li>Pings all Hubs whenever you publish/edit a blog post</li>
<li>Adds suitable Atom namespaced link elements for each configured Hub to the top of your RSS 0.92, RDF/RSS 1.0, RSS 2.0, or Atom 1.0 feeds</li>
<li>Maintains compliance with the Pubsubhubbub 0.1 Core Specification and any outstanding amendments</li>
<li>WP Pubsubhubbub utilises a Pubsubhubbub Publisher implementation which is fully unit tested for reliability and specification conformance, based on Zend Framework’s upcoming Pubsubhubbub component for which I am the lead developer.</li>
<li>Where no replacement Hubs are configured, WP Pubsubhubbub defaults to the reference Hub hosted on Google App Engine. This is a very reliable Hub. We also default to using the Superfeedr Hub as an alternative to ensure reliable service. You may replace or add to this list as needed.</li>
<li>Version 1.1.0 also enables Hub notification of changes to your RSS 2.0 Comment Feeds</li>
</ul>
As the specification authors state on the main Pubsubhubbub site, the protocol is decentralized and free. No company is at the center controlling it. Anybody can run a hub, or anybody can ping (publish) or subscribe using open hubs.

WP Pubsubhubbub

Implements a Pubsubhubbub Real Time Publisher informing Planet Earth of your updates now, not later!

Fetch Feed vs WP Pubsubhubbub