The recent version of Ubuntu and the upcoming version of Fedora both ship with PulseAudio, a sound server which supports, among other things, network-transparent operation: you can take any program that generates sound and redirect that sound to be played on any other machine with a PulseAudio server.
PulseAudio is part of a long and venerable history of using computers remotely. People have been using SSH and X11 forwarding for ages now. CUPS and SANE allow you to access a printer or a scanner from halfway around the world. x2x lets you move the cursor on one computer with the mouse on another. And SSH's port-forwarding feature builds bridges to enable pretty much any service to be used from anywhere, even if the server is behind a firewall or is only serving to localhost. Features like these aren't unique to the modern Unix-like operating systems, but it is only there that they are widely enough used that people actually rely on them to get things done. Perhaps more critically, it is only there that they are easy enough to configure that people can use them on an ad-hoc basis.
In contrast, Windows or Mac OS, users are very much tied to individual machines. It does not really occur to people that they could use more than one computer, or that they would even want to.
I think this reflects one of the philosophical differences between Unix-like operating systems and others. Under Unix, a computer provides a number of resources (such as software, data, computation capacity, or specialized hardware) from which you can pick and choose. Because of network transparency, physical proximity is unimportant. Channels of communication can be layered and rerouted arbitrarily. You can make computers work together as ensembles. Individual computers are fungible.
Just a few weeks ago, for my research work, I wrote a script to distribute the processing of hundreds of files among a bunch of free machines. SSH is set up with public-key authentication there, so all the distribution of work happens without human intervention. The whole thing, including parsing the input, distributing those jobs, and load balancing, is about 50 lines of Python, using software which is standard on most any actual GNU/Linux system.
I do not think it is accidental that this kind of flexibility started in OSes built on free software. People who are trying to sell you software licenses do not have as much incentive to allow individual computers to be used in whatever way you please.