It's worth checking out the Daily Pluck for this. It's a python script that downloads rss feeds using Plucker, then packs them into a palm database format suitable for use with FBReader.

You can run it on the IT directly, or on a desktop machine and copy the .pdb file over to the Nokia (either way, you'll need to install Python on the machine it runs on).

It may take a bit of work setting up, and you'll need some way to run the script (either with xterm or some way to run it from the home screen or menus).