Even . When you "block" a number on the service, anyone who calls from that number will get a perfectly convincing "this number is no longer in service" message.

You can install a huge number of iOS and Android apps that simulate calls to your phone. Most of these will ring your phone, spoofing a fake caller ID ("Look, it's the president again!") and then coach you through a conversation. The software tells you what to say so that others in the room will think you're responding. Some of the more popular apps include , and .

Similar apps will send you fake text messages. For that service, try .

If you want to pretend to be someone you're not while making a real phone call, there's an app for that. will mask your voice, making it sound like someone else's.

A Windows application also called does something similar.