Simple Note was at first an iPhone application, but as since expanded to an entire platform just for taking down text notes. As cliché as it sounds, its elegant simplicity is more than welcome in a world of bloated software. No save button, just notes.
Take down a note, it syncs to the web. Get something equally great (Notational Velocity) that syncs with Simple Note and you have something fantastic. I write practically everything (except code) within Simple Note. It’s a great place to keep all sorts of blurbs about anything whatsoever.
Simple Note is freemium, Notational Velocity is free