The first cosmological results from the ESSENCE supernova survey (Wood-Vasey et al. 2007) are extended to a wider range of cosmological models including dynamical dark energy and non-standard cosmological models. We fold in a greater number of external data sets such as the recent Higher-z release of high-redshift supernovae (Riess et al. 2007) as well as several complementary cosmological probes. Model comparison statistics such as the Bayesian and Akaike information criteria are applied to gauge the worth of models. These statistics favor models that give a good fit with fewer parameters. Based on this analysis, the preferred cosmological model is the flat cosmological constant model, where the expansion history of the universe can be adequately described with only one free parameter describing the energy content of the universe. Among the more exotic models that provide good fits to the data, we note a preference for models whose best-fit parameters reduce them to the cosmological constant model.Comment: Accepted by ApJ. v2: Two figures added, minor typographical corrections. 10 pages, 9 figure

Multiple images of a type Ia supernova: General relativity indicates that any sufficiently massive object bends the path of light passing by it. This effect is known as gravitational lensing. Goobar et al. have identified a supernova that is strongly lensed by a foreground galaxy, causing it to be highly magnified and splitting the light into four separate images. What is more, it is a type Ia supernova, a well-studied variety with reliable properties that can be used to constrain models of the lensing. This distinctive object will enable cosmological measurements and can be used to probe the distribution of mass in the foreground galaxy. Science , this issue p. 291