refer here http://code.google.com/p/google-gadgets-for-linux/wiki/HowToBuild

I manage to make it work on CentOS 5.2

first time compile it complete smoothly .. but.

first time run it said cannot load ..

then do

yum install xulrunner-devel xulrunner-devel-unstable

re-compile..

and again try run

ggl-gtk

did’nt work.. then try.

ggl-gtk –help

then try

ggl-gtk -ns

then take a peek at /usr/local/share/google-gadgets

ggl-gtk analog-clock

… and it ask for permission to allow this to access network and bla..bla.. click yes..

and yes.. it popup nicely.. at the sidebar..

another screenshot..