Recently I've gotten a couple emails from people asking if there was an
easier way to keep tabs of recently posted stories and new comments. There
is in fact an easy way to do this – News aggregators and it uses something called an RSS feed. Here's a great story
describing how it works
from the Online Journalism

Instead of the hunt and peck of Web surfing, you can download or
buy a small program that turns your computer into a voracious media hub,
letting you snag headlines and news updates as if you were commanding the
anchor desk at CNN.

The programs, which are just now moving out of the techie world into the
mainstream, come in a variety of shapes and flavors: NewzCrawler (PC), AmphetaDesk (cross-platform),
Radio Userland (PC or Mac), NetNewsWire (Mac), and
others. Look beneath the hood and they're all powered by XML, a souped-up
form of HTML. The programs check each site to see if they contain RSS (Rich
Site Summary) tags, a set of HTML-like instructions for sharing

Here's how it works. You fire up one of the news readers (also called news
aggregators), subscribe to certain sites from a directory of thousands of
choices — say, BBC Online, ESPN, Salon, the Chippewa (Wis.) Herald and
Bangkok News — and bingo, you're in business. Whenever you sign on, a
directory pane lets you see the most recent updates for each channel you've
subscribed to. Within each channel you'll typically see a half dozen
headlines and perhaps a summary, the entire item, and occasionally an
accompanying photo. Want to dive in further? Click on a link and you're
transported directly to the source's Web site. Some programs run through a
Web browser, others through a standalone program. Most are free.(Online Journalism

I personally use the free OSX version of NetNewsWire on my Apple
Powerbook. While this isn't for everyone if you visit many sites like mine
that support RSS feeds it can be a nice time saver. Of course it should
only be used if you want to quickly check for new posts or comments – you
won't be able to see the daily header picture or any newly added links with this

Just look for the RSS logo on the bottom right of this site, right click (control click on a Mac) and copy the url.
When you go into your aggregator create a new site and paste in the URL. That's it, you're done.