Only 2% of the DNA in the human genome codes for genes (protein machines). It's now becoming clear that a very large part of the remaining 98%, so called "non-coding DNA" is probably transcribed as many different RNA molecules. Some of these: ribozymes, riboswitches and probably more, are functional machines in their own right. Because of the difficulties of crystallizing RNA, 3-dimensional structural information on the structure-function relationship for these nano-machines is limited. Small angle x-ray scattering (SAXS) data has proved to be a powerful resource, albeit of limited resolution, from which to gain information about the 3D structure of intermediate states involved in the function of these RNAs. We will report on our understanding of structure-function relationships of RNA nano-machines gained from SAXS measurements. We will also briefly mention the advent of a completely new structural technique, Correlated X-ray Scattering, based on the availability of the first hard X-ray laser, the Linear Coherent Light Source.