Forum Moderators: open
Sometimes you can get into The Open Directory Project [dmoz.org] if you are in a regional category pretty quick.
I regularly submit Danish sites here and they're generally in within 24hrs but for some categories you can wait months...
Nick
www.dmoz.com
www.google.com
www.alltheweb.com
www.teoma.com (ask jeeves)
www.altavista.com
One of the most important things is to get links to your site...try searching for 'your keyword add url' you might be able to get free listings for your field. spiders will then follow them links and find your site and list it eventually.
! forgot www.yahoo.com!
$300 - Yahoo Directory
$50 setup + PPC - LookSmart Directory
$40 - Inktomi (MSN)
$40 - InfoSpider (AltaVista)
$30 - Lycos (AllTheWeb,Fast)
$30 - Teoma (AskJeeves)
The other option is to do free submissions and hold your breath. On free submissions I've had the best results with AltaVista