Replace "youtube" with "listentoyoutube" in the URL to download the audio of the video.
Replace "youtube" with "ssyoutube" in the URL to download the video in any quality available.
Replace "youtube" with "nsfwyoutube" to bypass age restriction.... (more)
If you're a Google Calendar user, you receive GCal invitations that were sent to another email address of yours, and you cannot accept them just because they were not sent to your Google email address (the one to which your GCal is associated), you are not alone.
You can actually accept GCal inv... (more)