Interferometry has long been used in radio astronomy to enable imaging
of astronomical sources with angular resolutions exceeding the
diffraction limit of a single aperture.  In the past decade,
interferometry of the CMB has been carried out with instruments such
as the CBI, DASI and VSA which exploited the inherent instrumental
stability and simplicity of ell-space analysis of interferometer
data. The practice of interferometric polarimetry has been
particularly well-developed in the radio astronomical community and
DASI and CBI were able to measure the polarization of the CMB at high
significance (>10sigma for CBI).  In this talk, I will discuss the
Cosmic Background Imager (CBI) project.  The CBI has been observing
temperature and polarization anisotropies in the CMB in the frequency
range 26-36 GHz from the 5000m ALMA site in the altiplano of Chile.
Science results from the CBI will be discussed, including the possible
detection of excess small-angle anisotropy due to the
Sunyaev-Zeldovich (SZ) effect, the measurement of the E-mode CMB power
spectrum on sub-degree scales, and targeted observations of the SZ
effect in clusters, highlighting recent (unpublished) results.  I will
also report the status of the ongoing CBI2 upgrade which will increase
the sensitivity of the instrument on small angular scales.