http://terrybanderas.blogspot.com/ shows very cool examples of ink and watercolor illustrations. They make me happy when I look at them.
http://tommykane.blogspot.com/ again the cartoonist illustrations are my favorite!
http://blog.taylor-white.com/ very interesting transparent vignettes
http://www.tofusquirrel.com/nest/ I don't know what I like more, the drawing itself or the presentation of the process.
http://www.gettom.blogspot.com/ as fare as I can tell this blog has nothing to do with vignettes but its hysterical. Check it out.