  Let F be the free group over a set of two or more generators. R. Brooks
constructed an infinite family of quasi-morphisms on F such that an infinite
subfamily gives rise to independent classes in the second bounded cohomology of
F, which proves that this space is infinite dimensional. We give a simpler
proof of this fact using a different type of quasi-morphisms. After computing
the Gromov norm of the corresponding bounded classes, we generalize our example
to obtain quasi-morphisms on free products, as well as quasi-morphisms into
groups without small subgroups, also known as epsilon-representations.
