Some of the largest particle accelerators in the world can speed-up charged particles very, very close to the speed of light. However, they all are large scientific machines - some of them several kilometers long. Over the past decade, an alternative, compact way of accelerating charge particles to very high energies has emerged, using high power laser systems. Recent advances in high power laser technology has enabled acceleration of charged particles – especially electrons - to near-light speed in a very compact plasma channel: a few mm as opposed to hundreds of meters required in a conventional accelerator. Recent experimental campaigns have accelerated electrons to energies over a Giga electron Volt, similar to a conventional synchrotron, but in a centimeter-long channel. Just like in synchrotrons, these electrons also emit copious amounts of nearly coherent x-rays during the process of acceleration in the plasma channel, offering new sources for time-resolved x-ray imaging of condensed matter, including biological tissues. I will give an overview of the field, describing the latest developments and future directions.