Charles, as you'll know, blackberries develop flowers and fruit on canes that developed last summer. You may be able to find container grown blackberries with a few longer canes on them, but these have usually been cut back. If this is teh case then new canes will develop this year that will carry fruits next year.
I'd suggest planting new blackberries now and being patient. Visit a 'pick your own' farm this summer, and you'll have your own fruits next year.