I want to compile workrave 1.8.1 without gnome support.
I use Slackware 10.2 that has no gnome. moreover I don't want to have gnome installed.
I used following commands:
./configure --disable-gnome
./configure --disable-gnome --disable-gconf
./configure --disable-gnome --enable-gconf=no
./configure --disable-app-gtk
./configure --disable-gnome --disable-gconf --help--disable-app-gtk
./configure --disable-gnome --enable-gconf=no --help--disable-app-gtk


 but all return the same out put:

checking for GCONF... Package gconf-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gconf-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gconf-2.0' found
configure: error: Package requirements (gconf-2.0) were not met.
Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively you may set the GCONF_CFLAGS and GCONF_LIBS environment variables
to avoid the need to call pkg-config.  See the pkg-config man page for
more details.

any idea what I can do?

Try --enable-xml. gconf is the default configuration storage; even if gnome is disabled. Will commit fix soon. 

I've tried with:
./configure --prefix=/usr --sysconfdir=/etc --disable-gnome --enable-xml --enable-kde

but it asks me for GDome2:

checking for gdome-config... no
configure: error: Need GDome2

Yes, Workrave uses gdome for parsing the configuration file. This is not really a gnome specific library. It only depends on libxml2 and glib. 

Patches to remove gdm are welcome..