Sort Options?

I'm kind of new around here, and I did somewhat searched for the topic of sort options, but nothing came up.

I want to give a suggestion of a sort option, something like:

- most views
- most replies

This is something that would be part of the memberlist as a set of functions, but the memberlist isn't up and no one knows if it'll be up anytime soon. (AKA, at the admin's discretion and decision.)