I'm thinking a treadmill would mean that as i'd be running in a straight line, and on a dry surface, there would be less chance of injury?
Perhaps, but good lord it must get boring after a while! =) To each his own. Hope you get a model you can tilt upwards.
To me, any exercise is boring. But i have done so in the past to feel healthier/burn off energy and to try and build my weight up.
In terms of getting a treadmill, i could do with one, but they are expensive. Plus i need room in the garage. It's still really cluttered, but it should hopefully be sorted out this year. All i can do is try to not get injured while running this time around!