Ok, for the past 5 days I have been trying to get my External HD to be recognized by PS3. I finally had success. First, the HD needs to be formated for FAT32. Sounds easy, but... If you erase the HD, and format it to MS-DOS(FAT), it will still not work on your PS3 unless you also create and format a partition. In all, you have to format it twice, once as an entire drive, and than again as a partition. It may work if you just do step 3 and on as steps 1-2 might not be needed but I didn't want to take any chances. I also tried it on VISTA OS, no surprise its even worse, and you could only do it for 32gb or less. I have over 100gb on my PS3 so that will not work. There are some programs for Windows XP, but trying to use it with boot camp was too much trouble. So, this is how I did it. 1. Open Macintosh HD-->Applications-->Utilities-->Disk Utility 2. I recommend erasing the drive so you start fresh, and have the most space available. I erased it and formatted it to MS-DOS(FAT). 3. Now here comes the important part. You must now select "Partition". Under "volume scheme" I created 1 partition (It included my entire drive of 1tb), and formated it as MS-DOS (FAT). Under "Options" it was "Master Boot Record". I then clicked Apply. 4. As it is, you can only use the disk for PS3 Backup Utility. To use it as an external drive to store info, you must create folders for the following, case sensative: VIDEO, MUSIC, PHOTO, and GAME DATA I have not added the folders as I only used it to backup my PS3 in preparation to install a new internal PS3 Drive, so I do not know if the video, music etc. folders work. I hope this helps someone. It took me forever to figure out because all the other posts I read on different sites did not mention creating a single partition of MS-DOS(FAT), they just said erase and format the drive to it.