When sending a message directly to someone using the chatter using the "@" operator (e.g. @fred) it would be good to include a link to the object so the user (Fred) just has to click on the link to take him directly to the originating object. E.g. the chatter message might be:
"@fred please make a comment on this sales order" , and the email content fred receives looks like:
"please make a comment on this sales order"