Official Mason Jennings Site
Mason's official home on the web features contact/taping information, tour dates and ticket information, videos, publicity info, album lyrics, and a spiffy site redesign with every new album!
Mason's Amazon.com Store
Amazon.com's "All About Mason" page has a few facts and collects all his albums (in CD and MP3 format) on one page.
Archive.org
Download (and upload, tapers!) complete Mason shows.