Liquid crystal based devices can arbitrarily control the amplitude, phase and polarization of light, enabling disruptive technologies such as flat screen televisions and smart phones. Yet, the Achilles heel of these devices are their slow, millisecond switching speeds, constraining potential applications. Here we develop the concept of a dynamic plasmonic pixel as a novel paradigm for liquid crystal devices using the electric field controlled alignment of gold nanorods. Experiments were performed using an electro-optic fluid fiber device, which enabled convenient interaction of light, electric fields and the nanorod suspension. We studied the evolution of the electric-field induced alignment of gold nanorods and demonstrate microsecond switching times, 3 orders of magnitude faster than a traditional Freederickcz-based liquid crystal alignment mechanism. We find that the dynamics of the alignment agrees well with the Einstein-Smoluchowski relationship. Furthermore, by digitally switching the nanorods between orthogonally aligned states, we show switching frequencies greater than MHz can be achieved. The development of these dynamically tunable plasmonic pixels may lead to ultrafast optical switches, filters, displays and spatial light modulators.