Not sure whether it's of any use but I requested a bump feature script from nick a few years ago that displays a bump link text on forum display by each thread and silently bumps the thread to the top and it also updates the lastpost data on forumhome when a thread is bumped.
I configured the script so that it's only possible to bump a thread by staff and admins but as default only the group with higher privelages and the threadstarter can bump the thread without going into the post.
Bump thread Script. Again, I don't know whether you'll find a use from it.