Is there already a hack that will "bump" a topic to the top if there is an edit to any of the posts by any user? If not, is it possible?

This would be very nice! I was suprised that vBulletin didn't already do this.

In editpost.php, add this:
right before this:
Should work. :)

Goes to test it out :D

Works like a dream. :D Thank you FireFly. :)

No problem. :)

The only downside to it is that it doesn't adjust the "last posted by" on the index, but that is actually a very minor thing that I can live without.

Yeah, that's how it works. :)
You could in theory add another field to the thread table, let's say "lastactivity" and order everything by it, but it would be such a headache... :)

Don't want any of those. I just wanted to let people know its behavior. :)

vBulletin used to do this by default but I changed it as users found it fun to bump posts just be editing them.