It's pretty easy to get kismet working:

cd /etc/kismet
rm kismet.conf
cp -p /KNOPPIX/etc/kismet/kismet.conf .

Edit kismet.conf:

(old line 22) auto_hopper=false
(new line 22) auto_hopper=true
(old line 37) capinterface=eth1
(new line 37) capinterface=eth0 (maybe)
(old line 53) cardtype=cisco
(new line 53) cardtype=orinoco

If you don't enable the channel hopper, kismet will monitor channel 6. You can change this with iwpriv monitor 1 channel

To do live capture with ethereal, you probably want to use iwpriv monitor 2 channel instead.

Tested with KNOPPIX V3.2 2003-05-16 EN