I totally missed this the first time around, but it's brainlessly easy and adds a nice little enhancement to your blog. A quick review - many blogs publish two versions of their site - HTML, which is what you view when you look at the blog through a web browser. At the same time, many publish an alternate version of the site in XML. This is known as an RSS feed (for Really Simple Syndication) - and allows other programs (most notably, news aggregators) to periodically monitor your blog to look for new content.
Last year, a couple people wondered if there would be an easy way for the HTML versions of your blog to point to the XML version. Turns out it can be done quite elegantly - and most blog vendors built it into their application in a few hours.
Why is this important? Well, when you're visiting a weblog whose RSS feed you'd like to subscribe to, it's now simple to click a button in your browser that will "discover" the RSS feed and send it to your aggregator automatically. It's nice.
If you're a Radio Userland user, all you have to do is follow the instructions here; it's a one-line macro that goes into your template. Once published, it adds the little snippet of code that allows web browsers to auto-discover RSS feeds. (Movable Type users can go here; others should follow the instructions for doing it manually here.)
The slick part comes next - adding the "auto subscribe" bookmarklet to your browser that will discover the RSS feed (assuming the site you're visiting has auto-discovery enabled) and add it to your aggregator:
One really nice feature if you're a Newzcrawler user - it has auto-disovery built in; whenever you're at a site with auto-discovery turned on, it automatically pops up a hint that lets you know you can subscribe to the feed. Nice!
Bottom line - add the line of code to your template and make your visitors' lives a lot easier. Win-win.