Pings give you and your team the ability to send short (140 characters max) messages to each other (and to the whole team) with a link to the entity you are looking at.
For example if you are viewing a company in CRM
you can select the "My Team" drop down and from a users sub menu select "Ping"
This pops up a new window that you fill in with a message.
The user then sees a new message in their "Ping" dropdown.
When this message is clicked on the browser navigates to the Entity (company in this example) and the ping dissappears from the Ping drop down.
This "Ping" is also recorded as a communication record against the entity so you can see old Pings. To facilitate this a new action type of "Pings" has been created.
Set to be "Y" if you want the ability to see all company info on the My Team drop down - System wide setting.
<add key="myCompanyEnabled" value="N"/>