From an artistic standpoint, I've become quite a fan of fog. It makes a relatively ordinary photograph much more interesting and creates the natural effects that some photographers spend hours creating artificially. And to make it even more special, fog doesn't typically stay around long, which makes me appreciate it's presence even more. A quick little blessing that eventually fades away, returning only god knows when.
"In nature, everything has a job. The job of the fog is to beautify further the existing beauties!"
-Mehmet Murat Ildan