To install feed2twitter:
install python-twitter:
  http://code.google.com/p/python-twitter/
installfeedparser:
  http://www.feedparser.org/

install it with: python setup.py install

Running:
  you need to set your feed and your twitter account.
  Create a folder under the $HOME of the user that will run feed2twitter called .feed2twitter
  Add a file called default.cfg, like this:

[global]
url = http://example.com/rss
username = twitter_user
password = twitter_password

Run it with the command feed2twitter. It will update your twitter with your latest 5 posts, hour by hour

Kudos to Gleicon da Silveira (http://zenmachine.wordpress.com/about/), that give me a idea of the code in a post of his blog