How do you get (free) publicity for your brand new startup?

so, we've launched a site (http://skychalk.com - check it out!)... and now we need people to visit it.

"build it and they will come" doesn't seem to work on the web! for those who have successfully launched sites/startups and garnered traffic, what is your strategy?

ignoring the simple answer - have a great site that people want to visit - how do you let person X across the street know your site exists?

is it possible to get publicity and write ups if you don't have funding or famous entrepreneurs at the helm of your project?