If he's smart (and strangely enough some of the nuts out there are really smart) he makes his phone calls either from pay phones or from a disposable cell phone paid with cash.

The Protection from Harassment Act defines harassment as a "course of conduct" amounting to harassment and provides that it must involve conduct on at least two occasions. The act also defines harassment as a behavior which causes alarm or distress.

So, since you received more than 2 phone calls and if the police can trace back the calls to him you've got all you need.
Also the fact that he shows in places and at times when he expects to find you without no reasonable motive (since he lives 45 min away there's no reason he shows up at your local grocery store and at your local gym) should be grounds for the protection from harassment act.

Note that the Act just provides for a jail sentence of up to six months or a fine, so if he really is nuts he could get worse.
Also file for an harassment restraining order: How to File an Harassment Restraining Order | eHow.co.uk