A stroller comprising left and right front wheels, and left and right rear wheels, left and right side laterally spaced-apart front frame members, each of the left and right side front frame members having a forward end portion and a rearward end portion, the forward end portion of the left side front frame member being coupled to the left front wheel and the forward end portion of the right side front frame member being coupled to the right front wheel; characterized in that the stroller further comprises: left and right side laterally spaced-apart middle frame members (110, 110'), each of the left and right side middle frame members having a forward end portion and a rearward end portion, the rearward end portion of the left side middle frame member including a wheel mounting structure along an outer face thereof and along an inner face thereof opposite the outer face, the rearward end portion of the right side middle frame member including a wheel mounting structure along an outer face thereof and along an inner face thereof opposite the outer face, so that the left rear wheel is selectably mountable adjacent to either the outer face or the inner face of the left side middle frame member, and so that the right rear wheel is selectably mountable adjacent to either the outer face or the inner face of the right side middle frame member; left and right side laterally spaced-apart upper frame members, each of the left and right side upper frame members having a forward end portion and a rearward end portion; and left and right side laterally spaced apart hubs disposed between and interconnecting corresponding ones of the front, middle and upper frame members (106, 110, 102), the left and right side hubs having complementary halves of an interlocking mounting structure defined on outward facing surfaces (222, 228) thereof, wherein side-by-side coupling of two strollers (100, 100') is supported by interlocking one of the left and right side hubs of one of the two strollers (100, 100') with the other one of the left and right side hubs of the other one of the two strollers (100, 100'). left and right side laterally spaced-apart middle frame members (110, 110'), each of the left and right side middle frame members having a forward end portion and a rearward end portion, the rearward end portion of the left side middle frame member including a wheel mounting structure along an outer face thereof and along an inner face thereof opposite the outer face, the rearward end portion of the right side middle frame member including a wheel mounting structure along an outer face thereof and along an inner face thereof opposite the outer face, so that the left rear wheel is selectably mountable adjacent to either the outer face or the inner face of the left side middle frame member, and so that the right rear wheel is selectably mountable adjacent to either the outer face or the inner face of the right side middle frame member; left and right side laterally spaced-apart upper frame members, each of the left and right side upper frame members having a forward end portion and a rearward end portion; and left and right side laterally spaced apart hubs disposed between and interconnecting corresponding ones of the front, middle and upper frame members (106, 110, 102), the left and right side hubs having complementary halves of an interlocking mounting structure defined on outward facing surfaces (222, 228) thereof, wherein side-by-side coupling of two strollers (100, 100') is supported by interlocking one of the left and right side hubs of one of the two strollers (100, 100') with the other one of the left and right side hubs of the other one of the two strollers (100, 100').