Stickies - Stickies is a PC utility written to replace Post-It-style notes left stuck to your monitor.
Indicator Stickynotes - Floating colourful sticky note windows on your desktop!
Notezilla - Colorful & powerful sticky notes app for Windows & Phones.
TopXNotes - TopXNotes is a personal notes and information organizing tool that you can use on iOS or Mac OS.
Memo HD - Memo HD is a simple stickers application that let you store your notes with password.
Pystickynote - Stickynotes for your desktop easily from the command line.