enabling tap and circular scroll on touchpad and modern debian/X

[Micha Feigin <michf@post.tau.ac.il>]

Debian has been constantly playing around with the touchpad (input device)
settings lately and broke my touchpad settings again.

How do I enable tapping and circular scrolling permanently (i.e each boot) on
the touchpad again with the modern debian?

It used to be in xorg.conf then it was hal with a file in /etc/hal/fdi/policy/,
what is it now?

I'm using debian unstable with xfce as windows manager (so gnome/kde settings are
not relevant)

Thanks