I run a logistic robot based system with individual buildings receiving and sending items with chests.

With logic I can connect the input or output inserter to the roboport and only feed items to the chests if the total number of items in the robot network is under a certain amount.

The other big use is cycling power between solar and steam. Plug in the steam power's water pump to an accumulator and set it to turn off when the accumulator capacity is over, say, 50%. This way you won't feed excess power to the network and waste fuel.