selections of people on white

This photo was one of 16 or so that i wanted to strip together to make one large group photo.
I started by selecting the white background.
I used the magic wand tool with a tolerance of about 30 (lower this if the selection goes into your photo) and clicked on the background.
then hold down the shift key to add to your selection.
I get as much as possible selected with the magic wand and lasso and then fine tune any problem areas in quick mask mode (Q).
Once i am happy with the selection i select-modify-expand (2 or 3 pixels).
I then select-feather (1 pixel).
Next select-inverse.
I can then grab the person (selected) with the move tool and drag them into a new document that i have made for the group.
If you just wanted a white background in the original photo you could have just filled the background with white before the select-inverse step.
Hair, obviously, is the hard part. Thank goodness these people wore hats.