Rmmbr is a free online note creating application that lets you quickly create a note. You just need to go to Rmmbr.com, type any text in the text box, and Rmmbr will create a Page for you with that URL. You can just start typing in that page to create a note.
Once you are done, you can just save your note. Whenever you open the URL of that note, Rmmbr will show you the note, and you can edit the note. Also, you can share the URL with anyone else. If anyone can see your note, they can also edit it too.
Rmmbr is a quite simplistic application, that is handy if you want to just quickly jot down something online that you want to read later. It does not gives any formatting options, and does not requires you to create an account, or to login (though, it does provides feature to login with your Google account, if you want to).
The only drawback that I see with Rmmbr is that anyone who has the URL can edit your note. Instead, I would have preferred something like JotOnce which provides similar core functionality, and then some.