Suggestion: sort by post thread start date

Hello!
When reading a thread (say Houston independent reviews) I use the sort by "last post by" date. I do not use the other options (title/thread starter, replies/views). If instead there was an option to sort by the start of the threads I would use that. The benefit is it filters out (i.e., down) all the threads that are old but have many recent comments and just shows you the new review content all at the top of the list. If you could add this it would be most appreciated. Otherwise thank you for an excellent site.
Regards.