One of the best ways to get backlinks is to implement some sort of link eXchange software, and while there are many options we've recently found a new favorite.
The domain LinxPage.com spelled Lin X page (with an X not a ks) has some super cool Web 2.0 version of this type of software.
The PHP Link Software relies on a .txt or a .db flat file to store all data so this means you will need PHP installed in order to run this. PHP is available for both Windows and Linux based servers totally free.
We currently have the software running on about 10 of our domains and it really is very very easy to use.
So how does it work? Well someone visiting your site clicks on yours links page. That person then has the opportunity to exchange links with you assuming they meet the criteria that you set in the admin area. They must place their your link on their website before your system will add their link to yours. It just automates the whole process and will even notify you if they ever remove your link from their website :)
Here is a quick summary of the free php based software.
Check out the project @ LinXPage.com