http://www.tailsteak.com/000433/waldo.jpg

via digg. the trick is to use "waldo" in your search terms. Which name change seems odd - surely 'wally' is less pejorative in the US. I remember there was a bar in Twin Peaks called "Wally's Hide-Out".

Though apparently people have been thinking about this quesiton for a while:
http://bob-rz.deviantart.com/art/the-affair-49203846
http://www.grudge-match.com/History/waldo-carmen.shtml
http://www.fanfiction.net/s/2327835/1/Where_in_the_World_is_Carmenand_Waldo
http://answers.yahoo.com/question/index?qid=20080125135431AAcWLgN

a reddit reader also points to
http://www.offthemark.com/Images/birth/birth01.gif

THe things I do on slow work days...