I do this with my cell phone too. I carry a Skype number that I use on my ipod and call people back on that rather than burn cell minutes. With caller ID on the

I do this with my cell phone too. I carry a Skype number that I use on my ipod and call people back on that rather than burn cell minutes. With caller ID on the cell phone it is pretty easy to know if the call is urgent or can wait 20 seconds till I call back on Skype.