There is an excellent WebmasterWorld on the topic of getting a "second tier link," as opposed to the link you really want. Wheel, the moderator of the forum, posted that it is not always easy or possible to get the .gov, .edu or aged link that all link builders dream about. When you efforts fail, why not go after those that have links from those "golden link" pages?
What I'll do is try to get links from second tier sites. Say I want a find a page on a .gov site that has a list of links. I'd like to be on that page, but I can't get a link. What I'll do is look at all the sites that are linked to from that page and try and get a link from them. I'll still get whatever good comes from that .gov link, just diluted and flowed through another site.
They are not the cream of the crop links, but they are still very valuable. The process is pretty simple:
(1) Discover golden link pages (2) Request links from those pages (3) Move on (4) Click on links from the golden link pages (5) Request links from those new pages (6) Rinse and Repeat
Forum discussion at WebmasterWorld.