http://code.google.com/p/ps3mediaserver/

I came across this media server solution for connecting up my Mac to the PS3, no more need for USB sticks or being annoyed by a lack of format support i.e. QuickTime… This media server plays everything, even stuff that other commercial solutions don’t support.

There was some issues with setting it up though and it can be summed up with one thing. Port forwarding. To make sure the Mac finds the PS3 and vice versa, I had to set up port forwarding in my router. So, I changed the IP on my Mac to be static, and then I went into the web-interface for the router and forwarded all communication on port 5001 to that IP.

Since I am on a Mac Pro, I have two connections on the network card, shown as Ethernet 1 and Ethernet 2 in the Network Preferences. Under the hood these values are shown as en0 and en1, so for the PS3 Media Server to know which one to use, you should select it here here: General Configuration > Force network on interface > en0 (or en1) > Save > Restart HTTP Server, and you should be ready to go.