There are some 30x and 70x models listed near the bottom of http://www.digchip.com/datasheets/pa...parts_ac15.php and a few more (including 5xx) at http://www.qinyielectronics.com/sdp/...0-1237503.html.

They are all quite low-res compared to the tablets though. The nearest part no match is ACX566AKM which is the one used on the Treo 690 (320x320).