Airplay without itunes I have some remote speakers hooked up to an Airport Express. While they work with iTunes as intended, I would like to stream sound that I play in other applications. Is there some facility for using the remote speakers from the rest of the system?

From googling (nothing found so far) and looking at this question, I get the impression that no ready-to-use solution is provided by Apple. Assuming this is the case, I'd be curious about commandline-oriented or implementation-level information: What do the remote speakers look like to the iTunes API? How does OS X handle sound output, and is there any chance of arranging for remote speakers to be exposed as a sound device at the OS level? I'm currently running Mountain Lion (OS X 10.8).

Update: a) Thanks to @TonyWilliams, I now know about AirPlay, a third party solution. Still hoping for information on doing it directly, though. b) I've also come across this question, which would allow a bit of commandline access to the airplay speakers (if I can get it to work).
You can simply go to System Preferences → Sound → Output and choose your output device. Lag applies here too.