I'm not sure if this is what you want but I've found a howto page on modifying a Philips SPC900NC web cam for long exposure.
http://www.home.zonnet.nl/m.m.j.meij...Y/spc900nc.htm
That was as a result of chasing information on the Philips ToUcam which appears to have been superceeded. The author also has some other resources on astro photography elsewhere on the site at
http://www.home.zonnet.nl/m.m.j.meijer/astronomy.htm
Bob