There is a project 'pencam2', formerly 'pencam/ pensnap', to support the Aiptek pencam dual with stv0680/ stv680 chip.

A few years ago I took the sources of that project, and merged them with svgalib, to put liveimages (at a rate of 3pics per second) to the console, which worked not very stable, but somewhat stable: Too fast capturing (> 3 pics/sec) often lead to abortion, while slow capturing (<3 pics/sec) went over hours.

When trying to recompile it for kernel 2.6, I failed - the libusb is making troubles - and I didn't find time to fix it.

my project is called 'vgasnap' and easily found on my homepage or at freshmeat.

At freshmeat you will find nearly everything