Cynical Peak’s Rivet is a Mac OS X app that lets you access your iTunes media on your Xbox 360.

In a nutshell, it turns your XBox 360 into Apple TV Jr. You can browse, play, and view your pictures, movies, and video through the Xbox 360’s media blade. Rivet will automatically load and give you access to your iTunes music, iPhoto photographs, and any video or picture folder that you wish to share.

Rivet is $18.95. A limited demo is available.

Rivet Features

• Music streaming – Listen to your iTunes music library through your stereo system and while playing games.
• Video streaming – No need to let your big screen TV go to waste because your video files are all on your Mac. Stream them over to it and fully enjoy them in the comfort of your couch.
• Photo streaming – View all of your photos right on your TV. It’s vacation slides for the 21st century. Your family and friends won’t be able to get enough! You can share photos from both your iPhoto library or from folders on your hard drive.
• Organize your media – Every movie or photo folder that you share is exactly replicated on your Xbox 360. Organize them into subfolders by TV show, genre, or whatever you want. The entire folder structure will be there. No more scrolling through a huge, flat list.
• Auto media updating – Add, delete, or move your media all you want. The changes will automatically appear on your Xbox 360.
• Format support – If your Xbox 360 can play it, Rivet can handle it. Supported formats include: AAC, MP3, WMA, H.264, DIVX, AVI, WMV, JPEG, GIF, TIFF, RAW, TIFF, PSD, PDF, and more.

Note: Rivet doesn’t support DRM’d music and videos purchased through the iTunes Store.