Manual submission. And to make the process even slower, I even pause for a few seconds to read their submission guidelines.
Informcenter, but I try to spice up the descriptions. As far as typing in the email addy and url Informcenter REALLY helps.
Manual submission only, to free directories only. I go to DP's "Solicitations and Announcements" sub-forum a couple of times a day. I submit to every free directory offered there. If there are three or four new directories on DP every day (and that is a typical day), without much effort over the course of a year you will get over a thousand inbound links.