I dont like the idea of a nanny cause I don't like the idea of a stranger alone with my child in my house that I don't know from a bar of soap.
Having said that, I worked for years as a nanny and loved it
Its too easy to get into an agency, the back ground check isn't near thorough enough and anyone can act like a good person and have a clear police history.
I'm just not very trusting these days when it comes to children after all the terrible things we hear in the media about things happening to kids.
In a day care environment there are more people around, more supervision, and I know that there are at least 2 workers in each room and nothing can happen behind closed doors like it can at home.
I know this may sounds a little paranoid but this is my opinion and having been on the other side where i've seen how easy it is to become a nanny wth a registered agency I just wouldn't do it.
Oh, and i was paid between 15 - 20 an hour depending on the family. Thats a lot of money just for child care!

Oh, but I think a nanny is a great idea for a parent working from home where you're still around but the child is cared for while you are there and working. One of my jobs was like this and we all loved it, me, mum and children