Radio astronomy is currently exploring an intriguing new phase space that probes the dynamic Universe on timescales of milliseconds. Recent development of sensitive, high time resolution instruments has enabled the discovery of millisecond duration fast radio bursts (FRBs) and the erratic rotating radio transients (RRATs). My thesis focusses on discovering these FRBs and understanding how we can exploit them as a cosmological probe of the intergalactic medium using RRATs as a test case. The class Fast radio Bursts encompasses a number of single pulses, each unique in its own way, hindering a consensus for their origin. The key to demystifying FRBs lies in discovering many of them in realtime in order to identity commonalities. The recently upgraded UTMOST in Australia operating at 843 MHz, is undergoing a backend transformation to rise as a fast transient detection machine. Until 2015, FRBs had been detected exclusively at 1.4 GHz. In my talk, I will describe the Monte Carlo simulations I performed, of a cosmological population of FRBs to predict the estimated FRB rate at UTMOST's's operating frequency scaling from the observed rate at 1.4 GHz. I will present the FRB surveys undertaken at UTMOST which yielded the first interferometric detections of FRBs and compare them to the expectations from the simulations. I will also talk about the method developed to potentially for the very first time, map the intergalactic magnetic field, using a recently discovered FRB. This method has enabled the determination of the first ever rotation measures of 18 known RRATs.