For the iSight, here is what's going to be needed in terms of:

Hardware:

1 computer (laptop in my case)

1 iSight camera

1 firewire pcmcia card (if desktop, then pci card should do) and 1 power cable (12V 500mA
 for the SIIG Firewire800 seems to work) and since it is most likely not provided with the
 pcmcia card, a trip to the store may be necessary.

     Heads UP:
    Something to be VERY aware of: I just fried my pcmcia SIIG Firewire800 (toasty smell of
    carbonized plastic being the second clue, the first one is the 'puff' and the smoke that
    came out of it) while using it with the power plug in AND a self powered firewire hard
    drive. I don't know where the problem is, polarity was respected; so I am assuming that
    it came from having 2 power sources at the same time, one into the drive and one into
    the card.)

1 firewire cable (provided w/ iSight)

Software:

Debian Sarge with kernel 2.4.27 (this may work with other flavors of *nix)

modules (if not build into kernel):

ohci1394

ieee1394

raw1394

video1394

programs:

gscanbus

coriander

Once you have the hardware, it is time to have the fun that is usually implied with any new
 device to be used under linux. I chose kernel 2.4.27 since it seems like most modules are
 easily found via apt, and thus generally do not require a kernel re/compilation.

To load necessary modules after plugging everything in do:

$ dmesg | grep 1394 *===> this will list all the modules/build-in parts
of the firewire support in the kernel*

if they are not listed, do as root:

# modprobe ohci1394
# modprobe ieee1394
# modprobe raw1394
# modprobe video1394

once this is done, try again:

$ dmesg | grep 1394

if you don't get any error messages, then you can try:

$ gscanbus

when I first tried gscanbus, I was getting an error message, and after
investigation, I realized I needed to change the permissions on
/dev/raw1394

# chmod a+rw /dev/raw1394

once this was done, I tried running coriander, but got an error message
about some device not found. As it turned out, /dev/video1394 was not being
created when I loaded video1394. To fix that problem, I did:

# mknod -m 666 /dev/video1394 c 171 16 [kernel 2.4.19 and above] 
*if you are using a different kernel version see http://www.videredesign.com/support_linux_kernel.htm*

After doing this, try running coriander again, it should work.

To use coriander:

my usage of coriander is very limited, since I borrowed this iSight for experementational
  purposes, but here is what I found:

if you click on Services Tab, then click under Switch/FPS on Receive and on Display, you
 should now have video.

One thing about the iSight that I am not sure how I feel about, is the little noise it makes
 everytime it focuses (at least on the model I am using)

Also, although the Satellite Pro 4600 is pretty fast (800MHz with 512mHz ram), the feedback
 is a little slow at a resolution of 640x480 YUV 4:1:1, and noticeably slow at 640x480 YUV 4:2:2

Now to do some actual video conferencing, I am going to need some more time and a new
 pcmcia firewire card, but here are some resources to start out with:

http://myhome.hanafos.com/~soonjp/vclinux.html