My colleague Ben pointed out a must-read post from journalist Sally Whittle who has blogged about what, as a journalist, she found it like being a PR person for a short time. Her overall impresion: "journalists suck!" Why? Because her experience was tough and involved calling people to place a story and she was given a rough trot. I'd recommend you read her article and the comments from her PR and journalist readers - there are 32 comments on her post already.
What I think is important to say here is that normally a PR person with some contacts (or one who is able to specialise in one industry sector) is not normally having to cold-call journalists. They will have contacts in their little black book who, when they have a story to place, they will get in touch with and it's quick, relatively painless and they know pretty much what to expect. That's my impression any way, I hope it's not too far off the reality of Sally's experiences vs others doing similar jobs to here right now.