First, I have heard from reputable sources that using the 'Add URL' page in Google actually makes it take longer because they throw your site into a pile that they plan to get to later.
More importantly, here's a technique that's so simple (yet brilliant!), many of you have probably never even heard of it or tried it. When you launch a site, go to a popular forum that gets crawled often where you've made quite a few posts that implements dofollow signature links (hint hint, this one) and throw your link in there by going to your user control panel and editing your signature and adding a link to a piece of punctuation such as a comma or period that no one will really see. I think Scott (ClickBump) coined the term 'sneaky punctuation trick' for this.
That link is instantly published on every post you've ever made in the forum anywhere, and while there is really no SEO benefit, it will get you indexed quicker than anything I've ever tried. It has never taken any of my sites more than a couple hours to get indexed, most within about 20 minutes. If you've seen a good number of my posts on here, you'll see that I change the link(s) in my signature almost every day.
Now go get indexed!