  Non-topological solitons (Q-balls) are discussed in some stringy settings.
Our main result is that the dielectric D-brane system of Myers admits
non-abelian Q-ball solutions on their world-volume, in which $N$ D$p$-branes
relax to the standard dielectric form outside the Q-ball, but assume a more
diffuse configuration at its centre. We also consider how Q-balls behave in the
bulk of extra-dimensional theories, or on wrapped branes. We demonstrate that
they carry Kaluza-Klein charge and possess a corresponding Kaluza-Klein tower
of states just as normal particles, and we discuss surface energy effects by
finding exact Q-ball solutions in models with a specific logarithmic potential.
