I will tell you right now if you call a hospital 9 times outta 10 you will get nowhere fast...getting connected to the inpatient pharmacy, finding the DoP/manager/whoever does hiring, and having them answer the phone is hard enough. But even if you go there (if you can find it, most are in the dungeon) they probably wouldnt want to see you, or the DoP is busy at a P&T meeting or golfing or something.
It basically comes down to applying online (most hospitals i looked at have online job listings) or knowing someone who's already works there.
As far as retail goes, around my part every big corporate pharmacy has an intern coordinator-like management person who sets up internships and tries to convince students/new graduates to work for them now/in the future. Get an email, talk to them.
If you *really* want to call and ask if they have openings, I would just call up whatever tech/student/lackey is triaging calls and ask them if they have openings and how one would go about getting hired...don't actually speak to anyone in charge just yet.
Or, finally, you could see if anyone in your school of pharmacy has a career coordinator faculty person who knows everyone and can help you score a job, which is probably the easiest option.