eHow launches Android app: Get the best of eHow on the go.
Summary: To block a number with Sprint, either call the carrier to permanently block the number or dial "*67" before making a call to conceal your number from the other person's phone. Get a cell phone number blocked with information from a wireless specialist in this free video on cell phones.
"Hi, I'm Ben from The Cell Phone Broker in San Jose, California, and today I'm going to show you how to block your number from your cellular phone. There are two ways you can do this. You can have a permanent block, which means you can call your cellular carrier and ask them to block your number permanently, which means that when you call another person, it'll show up as 'Private' or 'Blocked' on their caller ID. They won't be able to see who's calling them, they won't be able to see your phone number. The second way to do it is hit *67 before dialing the phone number that you're trying to call, and that'll do the same thing. It'll block your number, or have a 'Private number' show up on the other person's caller ID. So, I'm Ben from The Cell Phone Broker in San Jose, California, and that's how you block cell phones. You can check us out on line at myspace.com/cellphonebroker."
eHow Article: How to Block My Number With Sprint