There's no high-tech solution to the problem. I spoke to the local horticultural agent for the Cooperative Extension Service, who said that many commercial growers pick the fruit before it's ripe. Birds don't find the unripe fruit very appealing, so they leave it alone. The cherries ripen either during shipment or at the stores themselves. The best approach is to cover the trees with netting.
Some people use plastic owls and sound devices to scare off birds.
This isn't as effective as nets, however, and some communities have passed noise ordinances that prohibit such devices. We even checked with the National Arbor Day Foundation to see if any chemical repellents could be sprayed on the trees. The NADF says there are none. All rights reserved.