The recently released ASTER Global Digital Elevation Map (GDEM) from NASA and Japan's METI has been widely publicized on geospatial data blogs, email lists and in the mainstream media. At 30 meter resolution, these data promise relatively high-resolution DEM coverage for most of the globe (coverage falls between 83N and 83S latitudes). These data can be accessed either via NASA's EOS archive or Japan's Ground Data System
OpenTopography team member Ramon Arrowsmith has a preliminary comparison of the ASTER GDEM data with 90 m Shuttle Radar Topography Mission (SRTM) data on his blog. Ramon notes that due to various artifacts and high-frequency noise, the GDEM data may not be as impressive as one would hope relative to the SRTM data.