Has anyone ever dreamt something, only to have it happen?

Hey I'm new to this site, and love it - I'm working my way towards lucid dreams etc, it's so damn interesting. I've had a past of very, very tripepd out and strange dreams (I dreamt that I was talking to Osama the other day) they are usually very frequent and very vivid. Ok so this year I saw the future in my dreams twice - my mate (very best mate) was going into hospital to get an operation on his toe. I dreamt that I was him, and that instead of operating on my toe, they started to operate on my inner thigh of my right leg. I went to visit him in hospital and h had a bandage in that exact same place, because they took a skin graft from it. My other dream was that one of our horses was dead. I got back from boarding school to learn that dad had to shoot it. Both times I didn't know what to think...

I'm just wondering if other people have experienced this, and how often, and is there a method of actually obtaining them?

Cheers,
Roller