Notification Centre is fantastic. Whenever Snarl detects that you’re away or you’ve enabled Do Not Disturb mode, it will redirect any non-urgent notifications to the missed list. If Notification Centre is enabled (by switching it on in the [Presence] page) it will pop up whenever you return to your computer (or cancel Do Not Disturb mode) and you’ve missed some notifications.
The missed notifications themselves are grouped by application with the most recently missed notification at the top of the list. Double-clicking an application’s header will expand or collapse the notifications from that application and clicking the close button will dismiss all notifications from that app.
Double-clicking an entry will replay the notification so you can take whatever action you want as if you’d never missed it, or you can click the close button on the entry itself to dismiss individual notifications.