You actually can, but it's quite complicated. I wrote a post on how to do it using linux a long time ago: http://coderrr.wordpress.com/2009/07/29/how-to-force-flash-o...

I had a similar setup working with OSX using ipfw and natd. Really complex and disgusting setup though IMO. Using a VPN is so much cleaner.

Flash isn't a protocol. Certainly if they're streaming over HTTP (or TLS) it will go through a proxy (or at least it does everywhere else, I don't have OS X). What specifically are they doing that a "ssh -D" wouldn't handle?

You're correct HTTP connections over flash will use HTTP proxy settings. The problem is many sites don't stream over HTTP, they use some custom streaming protocol using raw flash sockets. And these do not respect SOCKS proxy settings.

I just remembered it's not actually custom protocols with raw sockets that are common and don't respect SOCKS settings but rather Flash's RTMP protocol.

I set that method up for my fiancée yesterday, who is in the US right now. The Flash content on iPlayer works fine, which uses RTMP.

So my method works too, but my goal is 'watching iPlayer abroad', not 'tunnelling RTMP through the UK'.

The proxy method does not work using the latest Flash in Mountain Lion, as it ignores proxy settings.