AlephNote is a lightweight front-end for multiple online note providers. It is a free and open source Simplenote client application that's straightforward, light on system resources, easy-to-use, well-designed, powerful and comprehensive.
Here are some screenshots to illustrate the features and user interface of this application:
CherryTree for Windows
Simple Sticky Notes
Efficient Lady's Organizer Free
EssentialPIM
EssentialPIM Portable