

Maybe something like xbackbone? I’ve used it to share small-ish files and it works fine; I don’t know how much of a pain it would be to use for a group of people, but as long as everyone has an account they should be able to access files with a link.
Unfortunately that doesn’t seem possible, afaik. Although you could always create a zip file with a password, and share it with an open link (anyone with the link can download it, no need for account).