Experimenting with a Photoshop Plugin I purchased some months ago. It is called Fractalius from a company called Redfield.
The effects are quite extraordinary and, as the name suggests, uses some funky fractal algorithms to create these effects. Several of the controls in Fractalius let you create and highlight lines, almost turning them into streaks of fire! This is the effect I used here and I really like the result. It is as if the sunflower is made of flames.
I have experimented enough so far to conclude that not all subjects will render pleasing results. In fact, some come out downright awful, so some trial and error is in order. It seems to work great though on things like flowers, probably because of the lines in the petals and symmetrical structure of your average, garden variety flower.
Sure is a fun way to exercise your creative streak.