There are many cool plots made in MATLAB across the web. I have set up for myself a way to find new ones on flickr, a website for sharing photos.
I find plots by creating searching for the tag matlab in flickr. I then set up an RSS feed from this search and see updates to the plots whenever I open my feedreader. For what it's worth, I use the Sage feedreader, a plug-in to the Firefox browser. One thing you will see if you do this is that there are some nice MATLAB graphics.
One thing you will quickly notice it many beautiful plots from one particular user: Arenamontanus.
Do you notice anything else interesting among these pictures? If so, share it with us here.