This is somewhat releated to the feature request found at
http://home.yole.ru/roundup/roundup.cgi/bugs/issue4

In addition to sorting/ordering feeds, I'd like to request the ability
to organise feeds by user-defined categories, possibly in a tree
structure.

Say I find a news feed. I could then drag that feed to the "News"
category and it would be added there, or I could be given the option
to add it to that category when I choose Subscriptions->Add Feed.

ian.