This is now becoming very popular and involves using your smartphone (iPhone/Android) and either simply hand holding it against the eyepiece of the telescope, or using an adapter.
These can either be home made, universal, or customised. There are different techniques and best-practice rules to using and getting the most from all these alternative set ups. If you want to learn more about how to get started and leapfrog the learning, I offer 1-1 workshops as well as webinars. I regularly give presentations to clubs and meetings too. If you want to get started and connect with me please click here.