only a handful of EGPs that are now known to transit their primaries and a periodic dimming at the $\sim$1.6% level was measured [@Henry00; @Charbonneau00; @brown01]. The transit of HD209458 lasts $\sim$3 hours (out of a total period of 3.524738 days). This was followed by the photometrically-selected transiting EGPs OGLE-TR-56b, OGLE-TR-113b, OGLE-TR-132b, OGLE-TR-111b, and TrES-1[@konacki; @torres; @sasselov03; @bouchy; @alonso; @pont]. Many more EGP transits are anticipated during the [*Kepler*]{} [@Koch98] and [*Corot*]{} [@AntonelloRuiz02] space missions. These projects are focussed on detecting transits around a fraction of the tens of thousands of stars they will monitor and will boast photometric accuracy ($\sim$10$^{-5}$) sufficient to measure not only transits by EGPs, but by Earth-like planets. The import of an EGP transit lies in the simultaneous measurement of both the orbital inclination (and, hence, with Doppler spectroscopy, the mass) and the radius of the planet. Knowledge of  and  (with some knowledge of the star) can be used to constrain theories of the structure and evolution of the close-in EGP [@bur.rad; @bur.ogle; @baraffe]. Currently, non-transiting EGPs are mute concerning such physical information.

HD209458 is close and bright enough that the STIS instrument on HST was used not only to obtain photometric precision of $\sim$0.01% 