Here's a reminder about a great source for Free, ASTER data... FREE ASTER L1A/L1B images are available in .tif format at the the GLCF ASTER L1A L1B website. Grab it at ftp://ftp.glcf.umiacs.umd.edu/glcf/ASTER/ - for a nice tutorial on working with these data see http://www.terrainmap.com/rm24.html. Finally, another source to consider is www.orthocoverage.com who are boaasting free ASTER data.