I just noticed that Blogger now allows people to sign their comments using OpenID, a truly cool idea that I'm hoping will take off. The basic principle is that, rather than one company (say Microsoft) running an identity-management system (say Microsoft Passport) that no-one else can interoperate with, we should instead develop a system that's "distributed". In other words, anyone should be able to start up their own identity server at any time.
Most other components of the internet have already gone this route. You can use email without your ISP having Microsoft Exchange installed (thank Darwin). You can set up a website without your web host having Microsoft IIS. But identity management still operates as a series of "walled gardens", with each forum or group you sign up to demanding its own username/password combo. It's an unuseable mess.
Better to have a system where anyone can set up their own identity server, or their own account on someone else's server, and have it recognised by all the "identity consumers" (forums etc). I'm expecting Google to start up its own OpenID server in the near future, and I can't wait!
Other interoperability things I'm hopeful about: the OpenDocument format for breaking down the walls between Office applications, MetaPlace for creating easier motion between virtual worlds, BugLabs for encouraging greater reusability of gadget components, and OpenMoko for making it possible to "unbundle" phone software and hardware.
I should mention that IMO there's a small chance that MetaPlace will go evil. It's not actually possible to set up your own MetaPlace server yet - at the moment its just a very big walled garden with lots of sub-gardens. Until the system is truly distributed, the MetaPlace company will have a somewhat unhealthy amount of power.
OpenMoko and BugLabs may be hitting the opposite issue - it's taking them worryingly long to release a commercial product. Openness is not a magic wand, sadly.
In each of these cases, though, the idea is damn good, and the fact that someone's doing something about it is guaranteed to be extremely disruptive, regardless of immediate outcomes. In the technology world, disruption is good.
So much so, in fact, that I'd strongly recommend everyone ensure that they're able to receive OpenDocument files. Since Microsoft is currently being a refusenik (for obvious reasons), this will mean you'll need to download a free Office product such as OpenOffice. Have fun!