Windows/Mac/Linux: A test version of Opera's formidable alternative browser introduces Unite, a plug-in that lets users share music, pictures, files, notes, and chat rooms straight from their desktop. Check out its services and features in a quick screenshot tour.
Before jumping into the big pictures, note that Opera 10 with Unite is a "Labs" release, meaning some features may not work as intended and might run a bit buggy. I created Unite services in an Opera window and accessed them with a Firefox browser, and all but the straight-up web serving, oddly enough, worked just fine.
Once you've signed in, or signed up, with an Opera account, you can hand out your sharing URL (in the form of computername.username.operaunite.com and, when you start up your Opera Unite services, your friends will see the same landing page as you. Streaming music and full-res pictures from your system can obviously be a bandwidth and system resource drag, but if you're using Opera Unite mostly while you're away from your system, that's probably not an issue.
Opera Unite is a free download for Windows, Mac, and Linux systems; using and serving up files and media requires a free Opera account sign-up. Click the screenshots below for a gallery-style tour of Unite's features, and be sure to hit the "800x600" links for full-size shots.
The controls for Opera Unite mostly run out of a pop-in sidebar, allowing you to start, stop, and configure services you want running. Oddly enough, to set a password for each service, you have to visit it from the browser instead of set it in your configuration panel. New services can be installed with a few clicks from Opera's site, but it appears this Unite test version comes loaded with everything that's out there, for the moment.
The Fridge is a pretty neat, simple, and ingenious little service. Anyone who knows your sharing name can stop by and write a little note to tack to your fridge, though you can tweak the accessibility from the configuration options.
The straight-up web server. Doesn't support PHP, mySQL, or any of the other modern web services (though those may arrive in the future), but could be helpful for selective web access to your-eyes-only documents, or hosting docs from crashed/overwhelmed servers.
Photo sharing is straight-up and simple. The server points to whatever folder they want shared, and the user sees thumbnails and bigger pictures when clicked, and can download the full-res version from there.
Music streaming is also fairly straightforward, but offers preview streams along with full downloads. If you've got a whole lot of music you want to offload to friends, you'd be better off running the more direct File Sharing service (not pictured, but pretty much how you'd imagine it).
The chat service works well and is really snappy in relay time, at least in our own browser-to-browser tests. Then again, there are a whole bunch of web-based services that let you create instant chat rooms (TinyChat and Chat.io come to mind) without having to make your browser the center of repetitive pings.