Hi John



Because:
1 The marketing issue --> Having a big internal storage increases the price
of the camera
2 Storage devices usually brake down after some time ... and when this
happens you cannot replace it because it's internal and you'll be walking
with some useless extra size and weight

With the current technology on the market, the internal memory of the camera
doesn't cover the necessities of the user...that's why most producers either
don't use any internal storage or a small one. It's something like a backup
for a photographer in the case he has no working external card and he really
need to take a shoot or two till he goes to the nearest shop to buy another
external card.

The video recording length depends on the codec used by the camera (that's
for coding the image and audio) you are buying and on the capacity of the
storage media.

Usually the specs don't give you the time but some review websites do (e.g.
http://www.dcresource.com/reviews/cameraList.php). For a Canon S2 having an
AVI video encoding the total recording time having a resolution of 640x480
and a card of 1 GB is around 9 minutes.

The conclusion is...if you want Video buy a Video camera. If you want Photo
and sometimes Video probably a digital camera with a 2 GB card will satisfy
your needs.

Greets,
Andrei