Pyrochlore oxides of the type A2B2O7 (where A = trivalent rare earth, B = tetravalent transition metal element) can form geometrically frustrated magnets displaying a range of interesting phenomena including spin ice, spin glass, and spin liquid phases. One exciting avenue of research in this field has focused on systems where, due to a smaller magnetic moment on the trivalent rare earth A-site, quantum fluctuations play an important role in controlling the low temperature physics of the materials. Recent studies have pointed to the possibility of quantum spin liquid behaviour (in which spin ice correlations exist at finite temperature, together with strong quantum effects), in a number of pyrochlore materials including Tb2Ti2O7 and Yb2 Ti2O7.