It's possible that you've been so consumed by L.A. Noire or MLB 11: The Show that you haven't realize that your PS3 can do more than just play games. With a few tweaks to your settings, and some software set up on your computer, you can stream music, videos, and photos from your computer(s) to your PS3 over your home network. Here's how:
Set up your PS3
Step 1: Make sure your PS3 is connected to the same network (via Ethernet or wireless) as your computer. You can check your connection by going to Settings > Network Settings.
Step 2: Go to Settings > Network Settings > Media Server Connection on your PS3 and set it to "Enabled."
Set up your computer (PC)
Step 1: Download and install the latest version on Windows Media Player.
Step 2: Go to Library > Add to Library and add folders you want your PS3 to access. All personal folders (Photos, Videos, and Music) are selected by default, but if you have media in other folders, add them.
Step 3:. Go to Library > Media Sharing, and check "Share Media." Press "OK," then wait a few moments for your PS3 to show up as one of the devices. Then select it, click "Allow," then "OK."
Set up your computer (Mac)
Step 1: Download and install PS3 Media Server (free). This will allow your PS3 to "see" your Mac.
Step 2: Connect to the same network as your PS3.
Step 3: Go to Navigation/Share Settings and uncheck everything in the Thumbnails section (at the top). Then, at the bottom, add folders you want your PS3 to access. You can choose to add your entire hard drive, but it's helpful to add shortcuts to folders like Music, Videos, and Pictures.
Step 4: Go to Transcoding Settings, and change the Maximum bandwidth to 14 or 15. If you have a very strong network connection, leave it at 0. If you don't have a 5.1 surround sound theater, go to the "Number of audio channels" settings and change it to "Stereo."
Step 5: At the top, hit "Save" and "Restart HTTP Connection."
Stream your media
Step 1: Go back to your PS3, and your computer's name will be listed under the Photos, Videos, or Music tabs. You need to be in the Music section on your PS3 to play music, in the Photos section to see photos, and in the Videos section to play videos. You cannot play copyrighted material.
Here are a few extra tips:
When viewing a photo, hit the button to view extra options, like starting a slideshow of images in the selected folder.
When listening to music, you can keep it playing in the background by hitting the PlayStation (home) button.
You can copy music, photos, and videos onto your PS3 hard drive. When viewing a file, hit the button and select "Copy."