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If you have plenty of time submit to DMOZ, get a couple of decent back links, wait 6 months to a year and you will be well indexed across the web in the fulness of time (provided your optimisation was properly done to start with).
If you are looking for instant results, then work out your budget, get out the credit card and get cracking with it today
The area you are interested in does have some self-proclaimed directory type sites (translation, free for all link farms), most of which are not very useful, but one referal is worth more than zero.
If you can't or have no time - just pay to LookSmart, Overture, Ask and others ;).
As I say "As with so many things in life, it depends on your time/cost factors."
With directories you can pay the $50 or you can do it yourself for free by giving up time as an editor.
The same sort of argument applies to Search Engines, you can pay for immediate inclusion, or you can optimise your site and wait for it to be picked up.
There are not really short cuts, you do a cost benefit analysis and makes your choice
ODP (and wait)
I'm too cheap for Yahoo, so I wait for Google to pick me up. I usually set up an Adwords program for a new site until it is in the main listings.
Zeal (when applicable. I refuse to pay LS)
Joeant
GoGuides.Org
(I don't like to edit so it's worth the $40 clams to get the site listed in a day or two so the engines pick it up. I usually pay both JA and GoGuides, but if I have to choose between the two I go with Goguides since their directory is updated immediately as compared to once a week at JA.)
After that is submitting to all the niche directories I can find.