I have just discovered that Celcom has set up a new website for its U.O.X prepaid plan.
As you may already know, the Celcom U.O.X and S.O.X prepaid plan currently offers the lowest voice call and SMS rate at 15 sen and 6 sen respectively to all domestic numbers.
Visit the new U.O.X website here- http://www.uox.com.my/ A similar (older) U.O.X site can also be found on the Xpax website- http://www.xpax.com.my/uox/
In the mean time, I also discovered http://www.sox.com.my/ which is registered under Celcom but at the time of writing the website is not accessible.
