i still don't see the difference in weighing backlinks from sites with extension .com, .edu or .gov.. well, they could be a source of traffic as .edu and .gov sites rank nicely, but for backlinks? still don't see no difference from a pr1 .com site to a pr1.gov/.edu
Education and Government Sites
.edu and .gov websites are recommended backlinks, as linking from these types of websites give you more clout with search engines. Becoming a valued member of their forums could get your foot in the door, as it is quite difficult to get these links.