  We present the broad-band UV through mid-infrared spectral energy
distributions (SEDs) of a sample of 72 spectroscopically-confirmed star-forming
galaxies at z=2.30+/-0.3. Located in a 72 arcmin-squared field centered on the
bright background QSO, HS1700+643, these galaxies were pre-selected to lie at
z~2 based solely on their rest-frame UV colors and luminosities, and should be
representative of UV-selected samples at high redshift. In addition to deep
ground-based photometry spanning from 0.35-2.15 microns, we make use of
Spitzer/IRAC data, which probes the rest-frame near-IR at z~2. The range of
stellar populations present in the sample is investigated with simple,
single-component stellar population synthesis models. Emphasizing stellar mass
estimates, which are less subject to systematic uncertainties than other
parameters, we find <log(M*/Msun)>=10.32+/-0.51 for the sample. Allowing for
the possibility of episodic star formation, we find that typical galaxies in
our sample could contain up to three times more stellar mass in an old
underlying burst than what was inferred from single-component modeling. In
contrast, mass estimates for the most massive galaxies in the sample (M*>10^11
Msun) are fairly insensitive to the method used to model the stellar
population. Galaxies in this massive tail, which are also the oldest objects in
the sample, could plausibly evolve into the passive galaxies discovered at
z~1.7 with near-IR selection techniques. In the general framework of
hierarchical galaxy formation and mergers, which implies episodic
star-formation histories, galaxies at high redshift may pass in and out of
UV-selected and near-IR color-selected samples as they evolve from phases of
active star formation to quiescence and back again (Abridged).
