Graffiti lets you flip any window in a Cocoa application over and write text on the back. You can save this text to a file. In order to use Graffiti, you have to download SIMBL.
v0.4- Japanese localization, basic document association - Download (185 KB, includes source)
v0.3- added preferences - Download (151 KB, includes source)
v0.2- fixed blurry window bug, added a scrollbar - Download (108 KB, includes source)
v0.1- first public release - Download (110 KB, includes source)