I've just bought the Nikon D50 - excellent and very easy to use. £360 with 18-55 if you know where to look. The D70 is quite a bit more expensive and doesn't really offer any extra useful features.
Next on the shopping list is the Nikon 18-200 VR (vibration reduction) lens =28-300mm in 35mm terms. Only snag is they haven't made enough for the huge demand at £550 a throw (I'm number 508 on Jessop's waiting list)