It's probably happened to you: you make a phone call from your cell phone to someone, and now they keep calling you back on your cell phone because they saw your caller ID number. This can be really annoying if it's a company you do business with, because now their accounts receivable has your direct number.
You may already know that from a landline, you can dial *67 plus the phone number you are calling to temporarily disasble your caller ID (for that call only). But did you know this will also work from your cell phone?
In order to make this work on your cell phone, you have to dial the entire sequence as one string. It's actuallty the same way you'd do it from a landline, but it just didn't seem obvious, at least to me.
Here is a screenshot from my iPhone as an example:
So next time you make a call and don't want your cell phone number to be visible, hit dial *67!