If you thought Maxis was on to something with its Zerolution hire-purchase scheme, then Celcom would probably draw your interest too with its equivalent NewPhone plan.
It's open to all customers (with certain caveats) whether they're new or existing ones, though those with over 12 months with Celcom and a good payment history will get certain privileges - such as getting the three month upfront payment waived. NewPhone allows you to switch to a new phone every year for free, so long as you keep the monthly payment for the first phone you signed up going.
You can even choose to keep the phone you have should you decide to opt-out of the NewPhone system, but cough up the rest of the phone's value. If you have no problem paying Celcom a monthly fee that basically works as a hire purchase scheme for smartphones, it's certainly not a bad deal. Celcom also doesn't lock you into any particular plan - just so long as you're with Celcom, you don't have to signup for a new contract just to qualify for a new phone.
For a closer look at the terms and conditions or figure out if you qualify, head to the official Celcom site.