Install this Firefox extension, and you find a fun button to push: "Stumble!"

Clicking this button will lead you to a variety of web sites that you might not otherwise find. You can suggest websites, and also leave comments and reviews of the website. You get to give the site a thumbs-up or thumbs-down -- which helps create a large database of sites. These sites are also categorized - so you can subscribe to astronomy, biology, graphics/art, or other topics like sports and business. I didn't click on sports and business, but I found a lot of cool typography sites and experimental interactives through the art/design category.

Interesting to note: I discovered this site because a site I worked on was getting numerous hits from this referral site.