Update: Rectified the title of this entry *sheepish* Didn't realised it was truncated by plog
In a perfect world, a user will give RssFwd a feed url [example] and RssFwd will display a nicely formatted preview [example]. At the bottom of the preview page, the user can choose to subscribe by entering his email and submitting a form. Q.E.D.
However, this isn't a perfect world, and instead of the feed url, users often give the main url of the site [example] or anything they see in their browser location bar. For such cases, RssFwd chokes and show an unfriendly page, "You *****! That's an invalid RSS/Atom feed url!", and prompts the user to try another url... as if he'll understand now that he's been lectured. And as far as I know, this is apparently the usual behavior of most rss applications - stopping at the scary, but friendly-worded error message.
But educating newcomer folks on "How to locate the xml/rss/atom icon", or "Right-click > copy link" (for feeds that show 'Download/Save-As?' when you click on them [example]) seem like an awfully uphill task; On the other hand, sitting back and relying on the masses to catch-up will only hinder adoption of that RSS thing. Unnecessary delays.
So, I guess the easier way is to educate the web-publishers. Since you are publishing feeds already, I'd figure you'll care more. Publishers, (most major blogging tools already does so) make sure your pages carry the link ref=alternate tags. Btw, this same tags that lets Firefox show that orange icon on the bottom-right. Such tags allows programs to know that your page has feeds, and what are the feeds.
Now, if RssFwd cannot preview a given url, it will autodetect for hidden link ref=alternate tags and check to find the actual feed on behalf of the user. Meaning, previewing (a main page) will just work (Rule #1). No more errors*.
Initially this was done for the benefit of RSS-challenged folks... but I'm beginning to find that.. I'm liking the convenience myself. So, for any webpage, you can dive straight into preview - If there's a feed, it'll pick up for ya. No more icon hunting.
*Disclaimer: Websites with no RSS/Atom feeds at all will still not render.