We made a small investment in a our new English friend Peter Cooper who developed FeedDigest. (By the way, FeedDigest is what powers the publishing of all my latest bookmarks at the bottom of this page). He recently turned me on to AllPeers.com – a simple, persistent buddy list in the browser. Initially, interaction with those buddies will be limited to discovering and sharing files – If you choose to, you can share any file on your network with one or more of your friends. They will be able to see what files you choose to share (even getting an RSS feed of new files you include), and with a single click download it to their own hard drive.
Various things like this have been tried before and are being tried now (Kasayka) but that’s a good thing because it’s STILL too hard to share images and files withing a closed group. I still use an FTP client, upload to a webserver and then email people the link around. It works for me but I am fully aware that this is not a mainstream solution.
I don’t know if there is a business model for any of these efforts besides acquisition but its the functionality we need and, as a diehard Firefox user I welcome such tools.