This might sound confusing: I have a directory and I want to find some other places to find backlinks, other than just directories. I submitted to many directories and continue to do so everyday. Getting quality relevant backlinks for directories from non-directory sources seems difficult. Other than other directories, where can directories expect to get backlinks?
Get blogs to blog about your directory. Buy links on well trafficed sites (but look to see if they would be mostly webmasters looking to advertise on directories). PM me as I do reviews of directories on two blogs.
Webmaster forums are good place to get backlinks for directory. Beside that webmaster resource site is also good.
Submitting to other directories is always a way. But you build one way links from internet related sites as well to get good serp and PR both. Every body is selling PR from directories so it's great way to build one way links for your directory by this method.
Get links in blog posts (try payperpost.com if you want) Submit to quality directories (most of them are paid) Submit to free directories.Buy sitewide links on webmaster related will help a lot IMO!