When I was a kid one of my first electronics toys of any kind was an electronic erector set that used magnetic blocks and a steel board made by Raytheon. The blocks consisted of electronic components which made up the signal chain. It was quite good. Since then the concept of electronic building blocks has always appealed to me. I still have a problem (literally) with solderless breadboards.. too many of them. Ive triedto make them neater by attaching projects semi permnently to dedicated cardboard boxes, and standardizing on their interconnects.. Its still too messy..