I was going to do a run through of StumbleUpon but I ran across this great video by Ross Goldberg that came with giveaway rights. Actually I picked it up for free at one of the many JV Giveaways that I participate in to build my list. The video walks you through the set up and how to submit your sites. It also shows you how to use the site to browse other websites.

The most important thing is that it shows you how to use the various groups to network and make friends. Web 2.0 sites are all about interacting with the other members. You get people to sign on as your "fan" and people rate your submissions with "thumbs ups". Watch the video and do what it says. Take a little time every week and become other people's fans, join groups, and look for friends. Over time, this will give you huge amounts of exposure and help brand your name and drive free traffic to your web sites.

Go ahead and download the video here.