Hi

As you have already mentioned, the most popular is heating your hot water tank with an iBoost/Immersun type system.

Battery back-up are a new way of ‘saving your electrons’ for evening use and will grow in popularity, especially as the Tesla Powerwall is available, but only at selected installers.

An EV or electric car would be another way of using your PV’s generated electricity before your electrons export out, but nothing else springs to mind unless you use the power ‘in-house’ to power a heat pump system.