  We present simultaneous photometric and spectroscopic observations of HD
17156b spanning a transit on UT 2007 November 12. This system is of special
interest because of its 21-day period (unusually long for a transiting planet)
and its high orbital eccentricity of 0.67. By modeling the Rossiter-McLaughlin
effect, we find the angle between the sky projections of the orbital axis and
the stellar rotation axis to be $62^{\circ} \pm 25^{\circ}$. Such a large
spin-orbit misalignment, as well as the large eccentricity, could be explained
as the relic of a previous gravitational interaction with other planets.
