See <a href="/documentation#HowToCreateANewScreenshotFactory">HowToCreateANewScreenshotFactory</a>. The factory password is your user account password on browsershots.org.
The current version 0.4 uses http://api.browsershots.org/xmlrpc/ for the screenshot factory API. You should install a package with "0.4" in the name, or check out the trunk from Subversion.