<gsub from="%TITLE%" to="">%DESCRIPTIONPLAIN%</gsub>

would work.

I'd have to look at our source code to check, as I can't remember if tags are rendered before gsub directives. I think they are, and, to my own surprise, this might actually work! It's worth a try at least ;-)

That all out the way though, there's no "official" way to do this. Removing items with dupe titles, etc, is easy, as there's a feature for that, but typically that's where it ends. Do try the above hack though!

http://app.feeddigest.com/digest3/XK7HCXUHPL.html

SimplePie requires you know what you're doing with PHP. It runs on your own server and you have to get arm deep with configuration files, code, etc. That said, it's a very good solution if you can understand it and make it work.

Feed Digest, on the other hand, is easy to get up and running with, you get some support, you get more output formats to play with (multiple inclusion techniques, HTML, JS, WAP, ASP, etc) as well as OPML support, but you have to pay and also be aware it's a "remote" service (although there are ways to get around the disadvantages of that, by fetching the digests to store locally).

So the pros and cons of both tools/services are pretty different, and it should become apparent quite quickly when you try to do what it is you want to do which one to use :)