We study the geometric properties of two stochastic flows on spheres in Euc
lidean space. The underlying one-point motion in both cases is Brownian. Bo
th flows arise from the action of a Lie group valued Brownian motion on a q
uotient. For both flows the curvature of a curve moving under the flow is s
hown to be a diffusion, null recurrent in one case and transient in the oth
er.