Okay, here is a link to the Wiki on
http://en.wikipedia.org/wiki/Graffiti_%28Palm_OS%29] Palm Graffiti [/URL]
If you go to Play Store and search for Graffiti you will find the current app. Download and install the app and have a go at it by setting "Graffiti" as your default input method in Settings/Language and Input. Once set up you will see a small (unfortunately) black set of boxes across the bottom of your screen pop up when you go to do some writing like filling out some online form. You can write with the Graffiti with both the SPen or just your finger. The Graffiti does not work with the SNote or anything on the Air Command screen.
It can be a pain sometimes due to the small height of the boxes where you do your graffiti thing. Sometimes on the N4 (not so much on the N2 or N3) the SPen seems not to register when I want to tap the screen to make a special character. So I just use my finger for that one.
If you are using the stock keyboard or some other one like Swype or whatever I might suggest that you stick with that since learning Graffiti has a pretty steep learning curve although the app does give you a pop up help screen.
Good luck with it and if you give it a try let us know if you like it or not.