Some command line

• @username + message

directs a twitter at another person, and causes your twitter to save in their "replies" tab. Example: @meangrape I love that song too!

• D username + message

sends a person a private message that goes to their device, and saves in their web archive. Example: d krissy want to pick a Jamba Juice for me while you're there?

• WHOIS username

retrieves the profile information for any public user on Twitter. Example: whois jack

• GET username

retrieves the latest Twitter update posted by the person. Example: get goldman

• NUDGE username

reminds a friend to update by asking what they're doing on your behalf. Example: nudge biz

• FAV username

marks a person's last twitter as a favorite. (hint: reply to any update with FAV to mark it as a favorite if you're receiving it in real time) Example: fav al3x

• STATS

this command returns your number of followers, how many people you're following, and your bio information.

• INVITE phone number

will send an SMS invite to a friend's mobile phone. Example: Invite 415 555 1212

Some code...

• Get the public timeline in RSS format, unauthenticated: curl http://twitter.com/statuses/public_timeline.rss
• Get updates from users you follow in XML, authenticated: curl -u username:password http://twitter.com/statuses/friends_timeline.xml
• See just the headers for that last request: curl --head -u username:password http://twitter.com/statuses/friends_timeline.xml
• Post a status update and get the resulting status back as JSON: curl -u username:password -d status="your message here" http://twitter.com/statuses/update.json

Learn more about cURL and the API here. http://www.sakana.fr/blog/2007/03/18/scripting-twitter-with-curl/

PHP CURL ACCESSOR

// url qui pointe vers l'action update, en xml ou json
$api_url = 'http://twitter.com/statuses/update.xml';

// l'information de votre compte
$username = 'usr';
$password = 'pwd';
$args = array('status'=>'Mon premier statut par curl');

// initialiser une session cUrl
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $api_url);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_NOBODY, false);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $args);
curl_setopt($ch, CURLOPT_USERPWD, $username.':'.$password );
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2); // en secondes
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

// pour éviter l'erreur HTTP 417 - Expectation Failed
$headers = array('Expect:', 'X-Twitter-Client: ', 'X-Twitter-Client-Version: ', 'X-Twitter-Client-URL: ');
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

// envoyer le message
$response = curl_exec($ch);
$info = curl_getinfo($ch);
curl_close($ch);

if( intval( $info['http_code'] ) == 200 ) echo 'Message envoyé';  
else echo 'Erreur HTTP ' . $info['http_code'];  

RESSOURCES

See the whole PHP Clean Class here : http://www.phpclasses.org/browse/package/4216.html

And here a Javascript Framework http://code.google.com/p/realtime-related-tweets-bar/