I have been using Piqqus for a couple of months and have found it to be helpful in driving traffic. The codes are difficult to come by, so I thought that I would share one here for whomever would like to try it out. Piqqus is a StumbleUpon and Digg exchange.
Here is the code: http[colon]//piqqus[dot]com/signup.php?r=12587&c=036fed4pep4e2a4d400f TAKEN