I've had a few situations where I needed to set up a web server where numerous users needed remote access. WebDAV and FrontPage extensions were out of the question in both situations due to the software the developers were using. I had several servers that either had multiple web sites or individual sites with numerous developers each editiing seperate directories of the site.

I'll skip the configuration issues on the production machines since you're just looking for some type of remote access to files. We used WS_FTP Server from IpSwitch on all of the development servers when developers were working from home or were remote contract employees. WS_FTP Server will do SSL over FTP to secure all transmissions. It will also allow you to use an external database of user accounts and passwords. So, if an account is comprised, the attacker doesn't necessarily have a userid for the system.