RSS feeds:

http://identi.ca/api/statusnet/groups/timeline/xfce.rss
http://identi.ca/api/statusnet/groups/timeline/xubuntu.rss 
http://identi.ca/api/statusnet/groups/timeline/ubuntu.rss 

http://identi.ca/api/statusnet/tags/timeline/xfce.rss 
http://identi.ca/api/statusnet/tags/timeline/xubuntu.rss
http://identi.ca/api/statusnet/tags/timeline/ubuntu.rss