What I need is - list of new stuff from last visit - when user has already checked out some new entity since his last visit (ex. post on forum), mark this entity as read in the list - count different types of entities - private messages, posts, comments and etc.
There are lot of websites using this technique for private messaging, listing new stuff and etc (ex. phpBB, this one and etc).
Are there any common pattern, description of the system core which will events, making lists?