What I cannot go without in Penang, is their awesome Asam Laksa. The Colleague told me of a place opposite the Penang Chinese Girls' School that was totally famous.
It's on the road further up from Gurney Drive. Keep going straight and you will see this little coffee shop righ at the corner.
Right in front is the famous laksa shop. It opens around lunch and sells out by roughly around tea time. See the bags of packed noodles on the top.