You can use your computer, phone, or other portable device to transmit a message to someone on Twitter without everyone else in the Twitterverse seeing it.
Step 1: Open a Twitter account Open a Twitter account. You can't send a direct message on Twitter unless you have an account.
Step 2: Get a follower Get someone to follow your Twitter feed. Tell a friend or family member to follow you, or have a celebrity alias.
TIP: You can reply to a tweet sent by someone who doesn't follow you, but you can't send a direct message unless they're following you.
Step 3: Click on the recipient's account Click on the account of the person to whom you want to send a direct message. You can click their account from their tweet to open a sidebar or you can click on their account in the Followers section of your home sidebar.
Step 4: Click the message button Click on the Message button beneath the recipient's abbreviated profile in the sidebar. The message window will pop up with a blinking cursor.
Step 5: Type your message Type your message with the confidence that no one else will see it. Be brief, though -- you still only get 140 characters.
FACT: As of 2010, the National Basketball Association, at 2.1 million, had more twitter followers than any other professional sports league.