She may be playing an anxious hostage's wife in Proof of Life, but that doesn't mean Meg Ryan has to sleep in tatty sweats. In fact, the vintage pajama bottoms and white children's tank tops she wears in the film merely continue the actress' penchant for pj's -- which she's modeled in movies since her When Harry Met Sally... days. ''Women in pajamas is a Hollywood tradition,'' says Proof costume designer Ruth Myers. ''And really sexy.'' We're sure Russell would agree.