Making netinst images

[Dan Serban <dserban@lodgingcompany.com>]

After playing around with preseeding, I'd like to make a small change to
the netinst iso.

Simply changing the Install menu item to include a few other options passed
to the installer process.

Is there an easy way to achieve this?  I found a howto on rebuilding
the .iso's provided by debian, but I was unaware that the information is no
longer pertinent to squeeze due to mkisofs being removed and now using
genisoimage to create hybrid (ie dd if=.. of=/dev/usbstick) images.

I'm not sure how to do this and I can't seem to google anything that
applies to my situation.

Does anyone have any experience with this?

Thanks.