List.It (Latitudinal Information Scrap Trapper that Indexes Things) is a neat little firefox extension which combined keyboard shortcuts with synchronization options to give you text notes in your Firefox sidebar.
Simply download and install the extension, configure your account for syncing options and use the keyboard short cuts to type your notes away.
The extension has been developed by the researchers at MIT’s CSAIL (Computer Science and Artificial Intelligence Laboratory). The researchers have built the tool primarily to study how people keep and use information, so when you sign up can optionally volunteer to donate your notes to help them improve List.it and other tools.
I spent some time using the extension myself and although useful, I still prefer using a Google Doc along with Split Browser which automatically syncs the moment you stop typing and is accessible via a url too. Alternatively, you could of course replace Google Doc with Evernote too.
Download List.It here.