my idea is a 'redstone switch'. it would act kinda like a 'redstone memory cell', except rather than having a complex setup of redstone, it would just be a single block.
How it would work: when the Redstone Switch recieves power from one end (the input end), the Redstone Switch will toggle between being 'on' and 'off', 'on' meaning the switch then sends out power from it's opposite side (the output end), and 'off' means it sends out no power. The Redstone Switch will stay turned to its previous setting even after it no longer recieves power. When the Redstone Switch stops recieving power and then recieves power again, the Redstone Switch will toggle on/off again.
This would make more complex redstone circuitry much easier to make, and require less space.