LookSmart.com: Submitting to LookSmart.com used to be straight forward, if expensive. But now it's all changed. LookSmart.com is no longer a directory in the same way that Yahoo and the ODP are. It is now primarily a PPC directory. In other words, you no longer submit a site for free or fee, wait for an editor to review it and then have it accepted or rejected. Now you have to do all that and then start paying for each click (as reported by LookSmart.com) that you receive from listings on LookSmart.com and its partners.
There has been a lot said on the subject so instead of rehashing it all here I'll point you to a very good article by Danny Sullivan which gives a lot of detail as well as links to other articles on the subject: LookSmart Changes To Cost-Per-Click Listings.

Regional LookSmart's: The various regional LookSmarts are still offering paid directory reviews but due to the major changes at LookSmart.com I would be very cautious of dealing with any LookSmart at this time.

Zeal.com: Zeal is another human edited directory that uses volunteer editors. The difference with Zeal is that you cannot suggest a site unless you are an editor. Another major difference between Zeal and the Open Directory is that, since LookSmart purchased it, you can only submit non-commercial sites.
If you have a non-commercial site or your commercial site has a substantial amount of information (not just a page or two) that could be considered non-commercial you should consider signing up as an editor.
To become an editor you have to pass a rather long-winded test so be sure you have some time to spare. As with signing up for the Open Directory and getting your category checked, taking the Zeal test will help you gain a better understanding of what directories want in terms of titles, descriptions and content. So if you have time and a site that would fit their content guidelines take the Zealot test.

Wisenut.com: LookSmart.com now owns Wisenut, a newish search engine that makes heavy use of link analysis and themes, similar to Google and Teoma.
Shortly after LookSmart.com purchased Wisenut the add url page disappeared. They have not yet announced any plans for paid inclusion so we have to hope that they are actively crawling, as Teoma does, despite the lack of an add url facility.

NEXT Step: Submit Your Site to Regional and Industry Directories