As a stalwart defender of the WTFPL in my small circle of developer friends (who mostly think I'm crazy for it), you are now added to the list of people I can use to back up the fact that I'm not. ;)
Seriously though, awesome project, used it for a while.
Another example for you: libcaca. [1]
However, the GNU people recommend the X11 license for small programs and Apache 2.0 if you've already decided to use a permissive license on a large program [2]