  We give a simple interpretation of the recent solutions for cosmologies with
a transient accelerating phase obtained from compactification in hyperbolic
manifolds, or from S-brane solutions of string/M-theory. In the
four-dimensional picture, these solutions correspond to bouncing the radion
field off its exponential potential. Acceleration occurs at the turning point,
when the radion stops and the potential energy momentarily dominates. The
virtues and limitations of these approaches become quite transparent in this
interpretation.
