Really? You have a child who interrupts you? I can't believe that. I'm just kidding. This is one of the qualities of childhood is kids want our attention immediately. They're very now oriented. They want what they want when they want it, and if it's your attention, then they're going to blurt out what it is they want regardless of what you're up to or what you're doing. The best way that I found with my son was that I explained to him if he interrupted me, let's say if I was only the phone, the answer was always no, unless no is what he was hoping to get. But, you know, that said, you have to be reasonable. If you have a very young child, you're not going to ask them to wait 20 minutes while you have a long chat with a friend. You acknowledge that they want your attention--"Sweetheart, I hear you. You're waiting to ask me something. It'll be two minutes. How many? Two." So you want to teach them how to wait, but you certainly don't want to reinforce the behavior by rewarding it, which many parents do. The child will interrupt once, they'll tap you, and you go, "No, I'm talking." They'll interrupt you a little more vigorously, and you'll say, "Stop." And then the third time they, you know, pound on your arm, and you say, "What is it? What do you want?" Effectively now you've taught them just hit mommy really hard three times and you'll get her attention. So don't reinforce the behavior. Set reasonable expectations for what they can endure while waiting for you, and certainly thank them when they have waited, "You know, that was so great. I know you wanted to ask me something and you still waited. Thank you sweetie. That meant a lot. I like that."