It is possible to do this. But it is not free service. It will cost you a little. Mobivox is a website which lets you do that. It is a trick and here it is as: First you got to register to mobivox and while registering you will enter the number of that person from whose you want to call and email address of your own(which you would be required to verify). Go to my credits and my account and bug some credits required to make call. After this verification click on direct web call tab and enter the number you want to call and then make call. The calling no. is the one that you filled initially. So in a way you are able to make a fake call.