  We report the discovery of six infrared stellar-wind bowshocks in the
Galactic massive star formation regions M17 and RCW49 from Spitzer GLIMPSE
(Galactic Legacy Infrared Mid-Plane Survey Extraordinaire) images. The InfraRed
Array Camera (IRAC) on the Spitzer Space Telescope clearly resolves the
arc-shaped emission produced by the bowshocks. We combine Two Micron All-Sky
Survey (2MASS), Spitzer, MSX, and IRAS observations to obtain the spectral
energy distributions (SEDs) of the bowshocks and their individual driving
stars. We use the stellar SEDs to estimate the spectral types of the three
newly-identified O stars in RCW49 and one previously undiscovered O star in
M17. One of the bowshocks in RCW49 reveals the presence of a large-scale flow
of gas escaping the H II region at a few 10^2 km/s. Radiation-transfer modeling
of the steep rise in the SED of this bowshock toward longer mid-infrared
wavelengths indicates that the emission is coming principally from dust heated
by the star driving the shock. The other 5 bowshocks occur where the stellar
winds of O stars sweep up dust in the expanding H II regions.
