Yahoo Answers gives users points for visiting their site daily. They show this subtle notification using an award/medal icon in the sidebar section when you are logged in and then fades it away after a few seconds.
Posts Selected From the Category "Notifications"
oDesk’s notification system have this circled numbers, 1 for notification and 1 for messages. I think it is a bit redundant, that when someone notify me for the 1st time I get 2 notifications. When you click on 1 of the notifications, you’ll get a list of each items and you can click the x button on the right to remove that notifications; 1 of the nifty features they have.
Gogobot has a notification area to notify you of different events regarding your account’s activity on the site. As any other website its located on the header part, and they added a bell icon with number