Dictaphone.js is a digital dictaphone application for the web in general and in particular. You can create any number of sound clips of any length (limited by the size of your local disk partition). You can play back sound clips, instantly seek to a given position of the clip and play or record several clips at the same time. It is based on the WebAudio and IndexedDB APIs.
For more details, see the dedicated web site: http://www.fos-apps.org.