I'm currently involved in three campaigns, plus I'm writing one of my own, and my character list is getting messy. I think it'd be a really cool and convenient addition to add a feature that allows players to create a folder for the groups of characters that belong to a single campaign alongside simply sorting from oldest to newest characters and such.

I was just about to post this same request for the same reason. Glad I used the search function.

+1 for this too. I'm looking for some way to organize my characters.

Folders, tags, something else...