Maybe this already exists and I just don't know how to use it, but some forums have a function that enables you to automatically go to the first unread post in a thread. This would be quite convenient, as many threads can get quite lengthy and it is nice to be able to jump to where you last read (which you probably don't remember), rather than only being able to start from the beginning or from the last page.
If this function does exist, maybe it would be nice to make it easier to use, as I can not figure it out. (Sorry)
I was using cruisecritic a bit recently, which has this function automatically, and I found it extremely convenient and just thought that it would be nice to have here at least as an option for those who appreciate it.