Directory submission still is very useful but probably not for the reasons you are asking (backlinking - seems to be your purpose). Directory listing is still vitally important to creating and maintaining your local presence and search engine relevance.
Directories you must be a part of include Google Places, Bing Local, Yahoo, Yelp and a handful others. Plus if you can find some good local websites related to your area and few popular directories related to your product or service you can never go wrong. Also more links you have on the web with websites with respectable page rankings will never hurt either. Directories are still worthwhile and not strictly from a SEO standpoint. Most of them are free and do not take too much time to set up so why not use them? Yelp allows for reviews and has a business deals program and directories off-shoot perks like this that help there importance as well.