How about leaving the top, unreachable ones just for the birds? Although they don't seem to want my yellow cherry plums...
Sounds like you need several small children armed with leaf rakes, like I have! The close tines on the rake pull the fruit off, but it does still bounce on the ground, possibly bruising it. Their other idea was to use some downpipe from guttering, the pipe knocks the fruit, then the fruit rolls down inside it to the ground. Sorry, these ideas aren't mine, they belong to my fruit-loving 8 year-olds.
And further to what Ina said - you could attach an empty tin can to a pole, comes with it's own sharp edge to cut the fruit off, too!