Google Voice

Google Voice is a feature on Google that connects phones to one number. You can set up an account through your email through Gmail. First you have to add phone numbers to a list to get them all under one number. Once you do that, you have a Google voice account that people can call you off of. So, if you're waiting for an important phone call and don't want to miss it, you do this and when people call that one number, it rings all the phones on that list.