The emerging field of optofluidics provides exciting opportunities for the realization of tunable optofluidic devices (TODs) using a large variety of physical mechanisms. This is because microfluidics is a promising technology for achieving a high degree of tunability - a capability that is not available in many of the current optical devices. In addition, microfluidics holds a great potential for rapid prototyping, miniaturization and integration. TODs already find commercial applications in various fields such as display and imaging, and are expected to become a key player in future optical systems for biology, medicine, communication and information processing. We review the recent progress in the field and discuss potential future directions.