Create a Yahoo Group (http://groups.yahoo.com/) in the niche your site sits.
Set up your own bulletin board at http://www.ryze.com
Create a Technorati (http://www.technorati.com/) account and "claim" your blog.
Conduct a survey.
Place a free ad for your company on Gumtree (http://www.gumtree.com/).
Submit an article about your niche to http://www.ezinearticles.com
Sign up to StumbleUpon (http://www.stumbleupon.com) and get your friends to Stumble your site.
Set up a 301 redirect to take traffic from your non-www address to your www address.
Add a link to your site in the signature of any forums you post on.
Advertise your site on Craigslist (http://www.craigslist.org).
Create an XML sitemap (http:/www.xml-sitemaps.com/) of your site and submit it to Google (http://www.google.com).
Get a custom t-shirt made with your website url on it, and wear it often.
On your Contact Page ask people if they mind receiving your newsletter.
Use YouTube (http://www.youtube.com/) to talk about your site in a video
Donate money to a charity and most will place a link on their site back to you.
Abide to W3C standards (http://www.w3.org/) - it will help your site in the long term.
Ribbon Gift Incentives
20 Ways To Make $100 A Day Online