A feature along these lines already exists here Bean_Junky. On the home page look for theOriginally Posted by bean_junky link=1173929506/0#0 date=1173929505
Any forum with that appearing next to it has had a new post made to it since last you were in there.
Similarly once youre in a forum any topic with a next to it has had a post made to it since last you read it. :)
Java "Info `R Us" phile