I should also mention that you will only get notifications if you have entered an email in the user settings area. So if you ever want to globally turn off notifications, simply do away with your email address.

For the paranoid, the email address field supports the "somebody+fromwhere@gmail.com" convention, where emails to "somebody+fromwhere" will be delivered to "somebody," but with the email still tagged with the "+fromwhere." You can use this (at Gmail, at least) to somewhat effectively identify where your email traffic is coming from, provided you tag the address you hand out to other places on the Internet with something relevant.