Your friend shouls have a restraining order against him, in order to have more against him in court. It should include a distance he needs to keep away from her, and prohibit phone calls. She should call the phone company, have them keep a record of calls made to her house and her parents' house. There should be no fee involved if it is part of a police investigation. If possible, she should stay with another person until the isssue is resolved in case this guy does try to get near her.
She should carry some sort of personal defense weapon, I would reccommend CS gas (not peper spray.) She could also consider a stun gun, my personal reccomendation is The Sizzler, available here:
http://www.amazing1.com/prot.htm
I reccomend it because at 6'8" and 300lbs, it can drop me instantly, while I can fairly easily disarm someone who sneaks up on me with a police-issue stun gun.