1. A method in a computing device for providing to user notifications of activity associated with documents of different types, comprising: providing access to information sources, each information source providing documents of different types; for each information source, providing a service having functionality for monitoring the documents of the document type of the information source; receiving a subscription request from a user, the subscription request identifying a selected plurality of documents of a selected information source and indicating a request to receive an automatically generated notification to inform the user of annotations that have been added for the selected plurality of documents of the selected information source by a selected time, the subscription request indicating to notify the user of annotations added for a document via an electronic mail message or a peripheral awareness notification; storing for the received subscription request a ticket that specifies the service of the selected information source, the selected documents, instructions for collecting annotations that have been added for a document, and an indication of how the user is to be notified; monitoring via the service for the selected information source each of the selected plurality of documents for annotations that have been added for the documents in accordance with the stored ticket; combining information regarding respective annotations that have been added for multiple documents among the selected plurality of documents by the selected time and generating a notification including the combined information; when the stored ticket indicates to notify the user via an electronic mail message, sending the generated notification via an electronic mail message to the user; and when the store ticket indicates to notify the user via a peripheral awareness notification, displaying to the user the notification.