in this video he uses Bake mode to paint flowers. Can this be done in Blender or is/was an SVN update, not official?
Here is a blend with an attempt to use the hair particles as he used them in the video - the tools were different a little, but they are close to what I have used here. Problem I found was when I was painting my particles with object visualization, they appeared away from the mesh emitter and on the opposite side. If you continue painting with the add tool, you will see what I mean.
test_for_particle_paint.blend (834 KB)
Ok, I got it to work - the important part to remember is the object you are using in the visualization tab needs to be in the same center as the hair emitter for the particles to represent in correct position.
second_test_particle_paint.blend (773 KB)