Thanks Duncan and Craig for your replies. I have actually just purchased the Nikon D40 (I am way too impulsive!)!
I know that the Eos 400 is supposed to be very good, but as i said, I am very impatient and hate waiting for anything and we did not have the money today to buy the 400d, so I bought the Nikon. I did read up though and it seems to be a very good camera, for now anyway. I will see what happens with my photography and if I need a camera with more mega pixels in the future, then I will look again!
Duncan, I realise that a different camera will not necessarily make my pictures any better, if they are not much good to start with, but I really would like to try and improve! For the first time in my life, I have actually found something I love with a passion, that I could potentially make a living from, if I really try to learn from constructive critisicm and read lots/maybe go on photography courses etc.
