RSSify at VoidStar.com
This form takes your web page and turns it into RSS 0.92. This is especially useful for Blogger users.
A tip of the hat to Aaron Swartz who came up with the idea and the first implementation.

Unfortunately I can no longer bear the bandwidth cost of running this service so I'm turning it off.

There's a mirror at http://www.wcc.vccs.edu/services/rssify/rssify.php. There may be others.

RSSify is also a horrible hack that really shouldn't be necessary any more.
Please consider using a weblog tool that generates RSS natively such as Blogger Pro or Movable Type.
Alternatively consider hosting RSSify yourself rather than using my bandwidth.

Put ... round each item in your page.
In Blogger you'd do this by going to your template in blogger and changing
<$BlogItemBody$>
to
<$BlogItemBody$>
And then publish something to re-create the page with the new template
Then put the URL of your new and modified page into the form below.
Check that what you get back looks like RSS.
Now you can make a link to this file like "http://www.voidstar.com/rssify.php?url=your_web_page_url"
Finally add a link to it on your web page, something like this.

This gif is freely copyable. Just right click, save

Notes:

The item text is put in the description element.
The first 40 characters of html stripped description are put in the title element.
The first link in the description is put in the link element. If there isn't one, the web page url is used.
All tags except <A> <BLOCKQUOTE> <CENTER> <DD> <DL> <DT> <HR> <IMG> <LI> <OL> <PRE> <UL> are stripped from the description.
A maximum of 25 items are included in the rss.
If you have any problems, send me an email
if you want more detail about RSS, take a look at the FAQ on this site.
If you want to run your own copy of this, the source is here.