Microblogging service Twitter can now track mentions of any specific keyword for you, as long as you've activated Twitter on your cellphone or IM program. For example, using the command track San Francisco, Twitter will alert you about any user tweets regarding San Fran as they happen. Use it to find out when people mention your name or your company's name. If you're inundated by all the new tweets, use the untrack command to disable future notifications about the particular phrase. Track your friends with Twitter and see how Twitter is used to set reminders, manage tasks, and organise notes.