  We study $K$-theoretical aspects of the braid groups $B\_n(\mathbb{S}^{2})$
on $n$ strings of the $2$-sphere, which by results of the second two authors,
are known to satisfy the Farrell-Jones fibred isomorphism conjecture~\cite{JM}.
In light of this, in order to determine the algebraic $K$-theory of the group
ring $\mathbb{Z}[B\_n(\mathbb{S}^{2})]$, one should first compute that of its
virtually cyclic subgroups, which were classified by D.~L.~Gon{\c c}alves and
the first author. We calculate the Whitehead and $K\_{-1}$-groups of the group
rings of the finite subgroups (dicyclic and binary polyhedral) of
$B\_n(\mathbb{S}^{2})$ for all $4\leq n\leq 11$. Some new phenomena occur, such
as the appearance of torsion for the $K\_{-1}$-groups. We then go on to study
the case $n=4$ in detail, which is the smallest value of $n$ for which
$B\_n(\mathbb{S}^{2})$ is infinite. We show that $B\_n(\mathbb{S}^{2})$ is an
amalgamated product of two finite groups, from which we are able to determine a
universal space for proper actions of the group $B\_n(\mathbb{S}^{2})$. We also
calculate the algebraic $K$-theory of the infinite virtually cyclic subgroups
of $B\_n(\mathbb{S}^{2})$, including the Nil groups of the quaternion group of
order $8$. This enables us to determine the lower algebraic $K$-theory of
$\mathbb{Z}[B\_n(\mathbb{S}^{2})]$.
