  Sco X-1 is the archetypal low mass X-ray binary (LMXB) and the brightest
persistent extra-solar X-ray source in the sky. It was included in the K2
Campaign 2 field and was observed continuously for 71 days with 1 minute time
resolution. In this paper we report these results and underline the potential
of K2 for similar observations of other accreting compact binaries. We
reconfirm that Sco X-1 shows a bimodal distribution of optical "high" and "low"
states and rapid transitions between them on timescales less than 3 hours (or
0.15 orbits). We also find evidence that this behaviour has a typical systemic
timescale of 4.8 days, which we interpret as a possible disc precession period
in the system. Finally, we confirm the complex optical vs. X-ray
correlation/anticorrelation behaviour for "high" and "low" optical states
respectively.
