USA.gov has teamed with with NewsGator to offer an easily-browsable set of RSS feeds at http://news.usa.gov/. This is both feed displayer and content lister, so you don’t have to subscribe to RSS feeds to get some use out of the site.
The different feeds are shown on the left side of the page, and range from General Government and Reference to Consumer News and Recalls to Science and Technology. Pick a feed the left and you’ll see its content on the right as well as a link to get an RSS feed.
Note that these feeds are aggregates — you can see that if you use the pulldown menu to choose to sort the feed by source. The Consumer News and Recall feeds includes posts from The Bureau of Transportation Statistics, CBP.gov, Consumer News from Pueblo, the FDA, and more. (The Consumer News and Recall feed has 32 pages’ worth of items.)
If you don’t want to bother with aggregates there’s a full list of US government RSS feeds at http://www.usa.gov/Topics/Reference_Shelf/Libraries/RSS_Library.shtml.
Or if you’d rather get US government podcasts, there’s a list of them here: http://www.usa.gov/Topics/Reference_Shelf/Libraries/Podcasts.shtml.