A swinging bob toy having two bobs constrained to, yet slidable along, a string. Each end of the string has a pair of low-mass, spaced-apart stoppers which allows the end of the string to be easily grasped so that smooth transitions can be made between various modes of operation. The string is smooth enough and thick enough that it slides over the fingers and wrists with a minimum of friction and abrasion. The even number of bobs on the string allows for configurations with a symmetrical weight distribution so that one bob may act as an exact counterweight to the other bob.