About To Change My Phone Number

There's this woman I know from university, and she is about to drive me crazy. I only hear from her when she needs to kvetch or when she needs a favor. She just now sucked up 15 minutes of my time on the phone, time I can't afford to spend on her right now. I am sure she is a lovely person and has other fine qualities, but I can't deal with her negativity. Maybe I'll start letting the machine pick up when I don't recognize the number...