TwitterWP – From example.php:

<?php

if ( ! class_exists( 'TwitterWP' ) )
  require_once( 'lib/TwitterWP.php' );

/**
 * Example TwitterWP usage
 */
add_action( 'all_admin_notices', 'twitterwp_example_test' );
function twitterwp_example_test() {
  // app credentials
  // (must be in this order)
  $app = array(
    'consumer_key'        => 'YOUR CONSUMER KEY',
    'consumer_secret'     => 'YOUR CONSUMER SECRET',
    'access_token'        => 'YOUR ACCESS TOKEN',
    'access_token_secret' => 'YOUR ACCESS TOKEN SECRET',
  );
  // initiate your app
  $tw = TwitterWP::start( $app );

  // Also works:
  // $tw = TwitterWP::start( '0=CONSUMER_KEY&1=CONSUMER_SECRET&2=ACCESS_TOKEN&3=ACCESS_TOKEN_SECRET' );

  $user = 'jtsternberg';
  // bail here if the user doesn't exist
  if ( ! $tw->user_exists( $user ) )
    return;

  echo '<div id="message" class="updated">';
  echo '<pre>'. print_r( $tw->get_tweets( $user, 5 ), true ) .'</pre>';
  echo '</div>';

  // Now let's check our app's rate limit status
  $rate_status = $tw->rate_limit_status();
  echo '<div id="message" class="updated">';

  if ( is_wp_error( $rate_status ) )
    $tw->show_wp_error( $rate_status );
  else
    echo '<pre>'. print_r( $rate_status, true ) .'</pre>';

  echo '</div>';

}