Instructions
Download and install the Mac version of the PS3 Media Server to your MacBook (see References). The PS3 Media Server is capable of taking any video file format, including .AVI, and streaming it across a wireless network to your PlayStation 3. The PS3 and MacBook have to be connected to the same wireless network. Select "Add" in the PS3 Media Server window to add the files you want to stream. They will begin streaming automatically.
Use MediaLink (see References). MediaLink is a program that you have to purchase before the full version becomes available. As of May 2011 the software costs $20.
Use Playback from Yazsoft Software (see References). As of May 2011 the Playback software retails for $15. That fee gives you the ability to install the Playback software on up to three different Mac computers. Playback is capable of streaming video files like the AVI, audio files like the MP3 and even pictures and other types of multimedia content directly to your television set via Sony's PlayStation 3 console.