Telly like everyone else I suspect.
I have a 4 yr old and 2 year old so that is the best entertainment for the 2 while I feed my now 9 week old. I have also managed to find a great bf support group that has a room for older DC's attached to it with lots of toys etc. I have been going once a week (for help admittedly) but my older DC's see it as an outing to a playgroup.