Local boy (Boeing Engineer) and Mom (gardener using a tent stake as a tool) designed this great hand tool, they sell it at local gardening events, but you can order one. The original Diggit is not quite as strong (mine I can use to pry out boulders from hardened clay), and they make a Diggit Duck to get deep roots out from between bricks.
They will never get rich off this endeavor, because nobody will ever need to buy a second one. No, wait, what about the ones I buy as gifts...

http://diggitgardentools.com/d...

(ps I did nominate it at the proper place, this is my attempt to get you to check it out.