Pinside is a very simple concept: you make an online pinboard where you can post notes and access them from anywhere. Then you can invite others to add notes as well.
A shareable pinboard like this could come in handy when you live with other people, whether it's your family, a significant other, or a roommate or two. The board can be viewed from any web browser, and members can their own notes. Each addition shows the author's name so you know where it came from. It's a great way to leave people messages or just keep your sticky notes accessible online.
But there is one major downside: the font used throughout the site is the dreaded Comic Sans. You might want to create a user style.