What is Twitter? Twitter is for staying in touch and keeping up with friends no matter where you are or what you're doing. For some friends you might want instant mobile updates—for others, you can just check the web. Invite your friends to Twitter and decide how connected you want you to be. How does Twitter work? When you send in a mobile text (SMS), Twitter sends it out to your group of friends and posts it to your Twitter page. Your friends might not have phone alerts turned on so they may check your web page instead. Likewise, you receive your friends mobile updates on your phone. What's with the 40404? When you send a text normally, you might send it to a phone or an email address. With Twitter, you use what is called a "short code." That's what 40404 is a special phone number you use to interact with Twitter on your mobile phone. How much does it cost? Twitter is a free service. At some point we may introduce optional, for-pay features or services but basic usage will remain free. Note: with phone alerts turned on, Twitter makes use of texting or SMS so check with your mobile provider to find out if this will cost you extra. Will this affect my SMS plan? If you have Twitter phone alerts turned on, you could end up texting more than usual. We recommend upgrading to an unlimited texting plan with your mobile provider. Do you charge my phone bill? Twitter does not charge your phone bill. How did you get my number? Your number was added by a friend of yours who is already using the system. Twitter does not share or display your phone number for any reason. How do I stop the service? If you want to turn off mobile updates but keep an active account on the web you can text 'off' to 40404 or visit Twitter.com and turn off phone alerts. To delete your account text delete m to 40404 or visit your settings page and clicDelete your accou How can I invite my friends? Click the "Add Friends" link at Twitter.com or add friends by sending a text message including their telephone and name to 40404 like this: add 212-867-5309 jennie How do I get more help? You can send a message saying, HELP to 40404. If you want personal attention visit our contact us page and get in touch. Do I still get phone updates when I use Twitter with chat? No. Logging into chat automatically turns off your phone alerts. When you're done with chat, text ON to Twitter to get your updates on your phone.