Tweepy provides a module to authenticate with twitter using OAuth. The example below retrieves the auth credentials from a config file and creates a filter stream for the terms 'technical' and 'elvis'. You can get a CONSUMER_KEY and CONSUMER_SECRET by creating a twitter dev account at http://dev.twitter.com/apps/new. The access token and access token secret can be found under the "My Applications" link in your account.

import tweepy
import ConfigParser
import os

class Listener(tweepy.StreamListener):
    def on_status(self, status):
        print "screen_name='%s' tweet='%s'"%(status.author.screen_name, status.text)

def login():
    config = ConfigParser.RawConfigParser()
    fn = os.path.join(os.environ['HOME'],'conf', 'twitter_mining.cfg')
    config.read(fn)

    CONSUMER_KEY = config.get('auth','CONSUMER_KEY')
    CONSUMER_SECRET = config.get('auth','CONSUMER_SECRET')
    ACCESS_TOKEN = config.get('auth','ACCESS_TOKEN')
    ACCESS_TOKEN_SECRET = config.get('auth','ACCESS_TOKEN_SECRET')

    auth = tweepy.OAuthHandler(CONSUMER_KEY, CONSUMER_SECRET)
    auth.set_access_token(ACCESS_TOKEN, ACCESS_TOKEN_SECRET)
    return auth

try:
    auth = login()
    streaming_api = tweepy.streaming.Stream(auth, Listener(), timeout=60)
    streaming_api.filter(follow=None, track=['technical','elvis'])
except KeyboardInterrupt:
    print "got keyboardinterrupt"

Find the complete codebase on github at: https://github.com/telvis07/twitter_mining