this thing's cooler than masturbation.
a few suggestions:
give each brush type it's own size memory.
rename paper intensity to Tone Intensity or Halftone shade.
rename paper randomness to diffusion
NEVER start out at any magnification other than 100%.
possibly crunch them palettes so we can get more out of them (suggest: more space for swatches, or fill palette space with more intuitive shade controllors)
support arc beziers (handles for the panzy's who can't handle two-click beziers ;)

More to come.