Dependencies:
You'll need gnome and gtk, with the developmentstuff..
And you'll need the gdk_pixbuf-library.

Compiling and installing:
make
su
make install

Uninstalling:
rm /usr/local/etc/thomaskjaer.txt /usr/local/bin/thomaskjaer*
or make uninstall

To use with Xscreensaver, vi your .xscreensaver configfile.
Somewhere in the list of hacks, add this:
"ThomasKjaer"  thomaskjaer -root \n\

You can also change add it in the global configfile, in
Debian it's /etc/X11/app-defaults/XScreenSaver or
/etc/X11/app-defaults/XScreenSaver-nogl
