I guess the assumption is you have an Apple notebook but which one we don't know. The assumption is you want to use a drawing or sketching program but its complexity you have not described. Try to fill in the blanks and be more specific about what you have and what you want to do so no one has to guess. Be a bit more specific.
i have a mac book pro 2009 (the newest one) with 10.5.7. i am looking for a simple mac application where i can run my finger across the trackpad and it "paints". just doing simple stuff like a word or a shape. nothing extreme like an art studio would require.