all could deliver good pictures in the right hands. D50 is not launched yet though.
A structured way to choose the camera:
1. Your friend to list down the features that are important to him and the quirks that are not acceptable.
2. Check out the reviews and specifications to see which camera meet the features desired and which has the most quirks that are unbearable.
3. Ask more specific questions from users.
A "feeling" way to choose the camera:
1. Go down to the shop to check out the cameras.
2. Purchase based on the feelings.
If you are thinking of getting VR or IS lens, then you should SERIOUSLY consider the minolta D7D as it is a MUCH better value considering you get a bigger viewfinder (which you will be using like ALL the time during shooting) + 2.5 inch 200k pixel LCD monitor.
actually 350D has one really useful advantage which people seldom mentioned.
It's playback is at 10x mag compared to D70 5x magnification. If you intend to playback the pictures on the LCD to review sharpness/focus, this is VERY IMPT, esp for newbies like me who are not really sure that they got a sharp pic.
Image quality (body)
Based on my observation on dpreview review between D70 & 350D; and using D20 as reference, 350D has a slight edge in image quality in terms of detail & low noise (high iso) using same/equivalent lens. The images from the review for 350D appeared ( subjective) closer to those from D20.
Value for money
D70 really shine in this dept. It is cheaper and come with a better quality kit lens that yield better image compared to stock 350D kit. Therefore, more $ needed to be spent on better lens so that full potential of 350D can be achieved.
Size, built quality....varies depending on end user needs.
Both are great cam that will yield good quality images under the right user and using the right lens.