As you know there is no official build for RHEL of Google Chrome.
Now we are going to install Google Chrome for RHEL5.
First of all download the source package for Google chrome(Chromium) from the following link.
Now get the following rpm and install it.
(Link corrected with the help of santosh below)
#rpm -ivh libXcomposite-0.3-5.1.i386.rpm
Now copy the chrome package to /opt and extract it.
Now just execute the following command to run Google Chrome
Create a custom launcher in desktop pointing to the above mentioned script