I think there are a handful of major directories worth submitting to, provided that the following conditions are satisfied: 1.the link gets placed on a page not too far from main page 2....on a page with at least PR 3... but there are PR 5, even 6 pages on some directories 3.the directory is a reputable major directory, not a linkfarm 4.the directory has a decent Alexa Rank 5.there are few other links on that page I guess these links can give a slight boost to a new site, especially... But it's still very delicate/risky... Here's a Matt Cutts video about this: http://www.youtube.com/watch?v=rKUlVquEImc
Listing your sites in directories is tricky. You need to check their visibility in the U.S. and their PR rankings.