Cork Board Squares

What kind of wall are you sticking it to... dry wall, brick, wood? Is the surface painted? The bonding agent will work differently depending on what type of wall and if it is painted or not. It is going to peel off at the weakest bonded point.

Industerial velcro nailed to the wall then super glue the other part of the velcro to the cork board (wait for the super glue to dry before putting the cork back up on the wall).

Otherwise you can just nail them to the wall but would need to be carful on using a nail with a big head that you only pound to the surface of the cork so it will actaully hold the cork to the wall. This will work the best if you nail into a stud, so would need at least a 2 nich nail & stud finder. The stud finder also works great to boosting hubby's ego and you make a beeping nosie when you pass to over him.

What about putting them in a large picture frame and hanging that?

Do you have an objection to nails? If not, go to JoAnn's and get curtain hanging velcro. Nail the non-sticky side to the wall and stick the adhesive side to the cork board.

I don't suggest sticking anything to the wall because it will pull off the paint. I have done this and ended up with places I had to repair. If you don't mind repairing it later, that is an option.... nail hole or paint rip, your decision on what to fix later. :-P

They also have Velcro with industrial strength sticky glue on the back. You can stick the sides to the wall and the square.

I had the same problem and just used tacks to "tack" them to the wall. I haven't read the other responses, yet, so I hope this isn't redundant.
I had some cute ones and secured each corner with them and they look decorative.

Hammer them in with straight pins. Just hammer one in to each corner. They will make very tiny holes in the wall, and are strong. I even hang some picture frames with straight pins. Good luck!