  Some transiting extrasolar giant planets have measured radii larger than
predicted by the standard theory. In this paper, we explore the possibility
that an earlier episode of tidal heating can explain such radius anomalies and
apply the formalism we develop to HD 209458b as an example. We find that for
strong enough tides the planet's radius can undergo a transient phase of
inflation that temporarily interrupts canonical, monotonic shrinking due to
radiative losses. Importantly, an earlier episode of tidal heating can result
in a planet with an inflated radius, even though its orbit has nearly
circularized. Moreover, we confirm that at late times, and under some
circumstances, by raising tides on the star itself a planet can spiral into its
host. We note that a 3$\times$ to 10$\times$solar planet atmospheric opacity
with no tidal heating is sufficient to explain the observed radius of HD
209458b. However, our model demonstrates that with an earlier phase of episodic
tidal heating we can fit the observed radius of HD 209458b even with lower
(solar) atmospheric opacities. This work demonstrates that, if a planet is left
with an appreciable eccentricity after early inward migration and/or dynamical
interaction, coupling radius and orbit evolution in a consistent fashion that
includes tidal heating, stellar irradiation, and detailed model atmospheres
might offer a generic solution to the inflated radius puzzle for transiting
extrasolar giant planets such as WASP-12b, TrES-4, and WASP-6b.
