[quote=sdduuuude]Another way is to get in touch with someone taking out their driveway. Jackhammer or sawcut the pieces into 1′ x 2′ pieces and stack them (with or without mortar on top of a poured footing. They benefit because taking the demolished driveway to the dump is very expensive.

It is a popular Clairemont canyon solution.[/quote]
I have seen some of these and they work pretty well.

Another solution is using the spare concrete test cylinders that civil engineers have to produce on concrete pours. The cylinders are used to verify concrete strength after hardening and some civil engineering facilities end up with a lot of spare ones.