Ooooh, phone idea!
You could buy a phone card. Then any record of phone calls would only record the 1-800 number for the calling card, and there'd be no way for him to trace it to its final call.
You could make something up if he questions you, since cell phones generally have the same rates for any call in the country.
If you don't have anyone you'd call from outside the country, you could say you wanted to call one of those online horoscope or psychic things, just for fun, and they said if you used a calling card it would use the money from that rather than add it to your phone bill. How would he know if it worked or not?
Just a thought.