Yesterday's post talked about Photosynth becoming available on Moonlight, via a new Silverlight-based Photosynth viewer.
Since Silverlight 2.0 is already available for Mac, it makes sense that the 'test' Sydney synth also works on the Mac - which it does (in Safari, even!):
But now if you attempt to access a synth you should see this message (since, like, mid-December)
and assuming you have Silverlight 2.0 installed, away you go!
Unfortunately you still need a Windows PC to create synths, but there are quite a few available to browse, including Barack Obama's inauguration.