Dont do it, its not worth taking the risk. I have always submitted by hand
Add your URL to Google takes 1 minute. You only need MSN, LIVE, YAHOO, but just as important are the directories DMOS etc there are hundreds of them do some research and find the ones that are relevant to your industry.
There are few basic rules to optimising a web site
1 Ensure the site is optimised (use IBP or similar software)
2 Off site and onsite blogs again make sure they are optimised (make sure the sites and blogs have xml and html site maps)
3 Link exchange with as many sites as possible DO NOT BUY LINKS
4 Write relevant posts linking back to your site and submit them to as many relevant Blogs Notice boards, Forums. Etc.
In essence search engines like quality content and will reward you with higher rankings if you giving them it. Matt cutts (google webmaster has a great blog and worth keeping an eye on for its and advice.
Matt Cutts: Gadgets, Google, and SEO