In June 2009 we announced the release by the METI and NASA of the free global topography dataset named "ASTER GDEM", and Version 2 with significant improvements has just been released earlier this month.
From the article: "The improved version of the map adds 260,000 additional stereo-pair images to improve coverage. It features improved spatial resolution, increased horizontal and vertical accuracy, more realistic coverage over water bodies and the ability to identify lakes as small as 0.6 miles (1 kilometer) in diameter. The map is available online to users everywhere at no cost. [...] The ASTER data cover 99 percent of Earth's landmass and span from 83 degrees north latitude to 83 degrees south. Each elevation measurement point in the data is 98 feet (30 meters) apart."
Here's a direct link to the ASTER GDEM website. See also previous news regarding ASTER GDEM. Of course, if you have an interesting in the ASTER GDEM, make sure you know about the SRTM-DEM CGIAR-CSI Version 4 too.
More than 500 GB (10 thousand scenes) from year 2001 to 2003 are freely distributed on gis-lab.info. Cover areas of Russia and Canada. See:
[Editor's note: you might be interested in taking a look at previous ASTER-related stories]