There are another way to discover Penang Island–by motorbike.
Before you rent motorbike, please make sure you have a valid driving license, then you can go any place you like by motorbike.
There are a rental shop at Chulia Street, Love Lane or somewhere around George Town. The shop owner will ask some deposit , it is about RM 100. And the rent for a motorbike is from RM 30 per day with helmet.
Do remember to wear helmet, it is for your safety and also Malaysia traffic rules.