1. A method for inferring activity-related context information from a message, comprising: scanning, by a computer, for a keyword in the message, wherein the keyword is associated with an activity category in a content database; determining that the keyword indicates the associated activity category; inferring message-related context information from the keyword in the message; and recommending an activity in the activity category based on the inferred message-related context information, wherein recommending the activity involves: identifying one or more content items associated with the keyword, wherein each content item corresponds to a recommendable activity; generating a combined model based on the message-related context information, wherein the combined model includes an activity model for one or more activities associated with the message-related context information, and includes a user preference model for the user; scoring the one or more content items using at least the activity model and the user preference model of the combined model; and returning a content item associated with a top score.
2. The method of claim 1 , wherein scanning for the keyword in the message involves using the content database for guidance and looking for surrounding text which indicates the presence of the activity-related keywords in the message.