I think it is called Seal and Peal. It is a caulk type product. I am a teacher and moved to a very old building that had just been painted with horrible paint. I could not get anything to stick to my walls. I vented to some of my friends and they told me to get this seal and peel. You can find it at Lowes where you find stuff to winterize your home. It stinks really bad but the smell does go away. I am trying it this year for the first time. Everyone swears by it. However, a friend of mine said do not use it on drywall, it will pull the drywall down.
Our school has the same block walls, they use the sticky stuff that looks like gum, I have seen it in white, blue or yellow but I don't know the name. They also use tape like mentioned above. I wonder if they sell tracks for the walls like soem rooms have over the white boards, it is metal and has attached pieces that paper will slide into and they can move on the track too, not sure if thi is similiar to the above post or not?
when I lived overseas, they had these hook with metal "nails" and you pound the nails into the concrete then you're left with just the plastic hook. I know it sounds confusing.
we tried to attach things during our book fair onto our brick column and nothing worked. tape, scotch tape, painters tape, masking tape. we found duct tape works as well as those sticky poster "putty" things for hanging posters.