FolderShare is a neat peer-to-peer file sharing application that was recently acquired by Microsoft. It sits in your system tray and silently synchronizes a specific folder on one computer to a folder on some other computers. Some co-workers and I are giving a talk tomorrow, and we decided to use FolderShare to sync the talk assets. Overall, it worked, but not without a couple of issues.
The first thing we noticed was that by default, FolderShare allows you to access your entire computer via a password-protected web page. I was pretty horrified to discover that only a simple password was between my files and the rest of the world (remember, this skips through your firewall). To disable this, you need to open the FolderShare Settings dialog and uncheck the "Allow web downloads from this computer" checkbox on the Transfers tab. It also seems wise to uncheck the "Run FolderShare when your computer starts" checkbox.
Second, FolderShare is not a revision control system. If two people open the same file on two computers, FolderShare will resolve the difference by automatically renaming the files using the computer name and user name. This is not what you might expect, and will screw up any file dependencies you might have in a project. As a matter of fact, when working with PowerPoint files, FolderShare seems intent on re-syncing the file each time it is opened, whether you changed the file or not.
Finally, bandwidth is an issue. If three people (and three computers) are sharing a folder, and one of them has slower bandwidth, the slow computer will take longer to catch up to file changes. Eventually, it will get enough out of sync that FolderShare will start renaming files as if they were edited by two different people (see above).
All in all, peer-to-peer document sharing via FolderShare worked pretty well, though we did have a panic moment when we noticed 7 copies of our talk in the folder tonight. I ended up turning off FolderShare, fixing the PPT file, copying the "master" to a new directory in the folder, and restarting FolderShare. After tomorrow, I'll be uninstalling it.