Ok so I bought a seagate portable harddrive for about 70 at staples last month to hold and stream my media library (videos only) to watch on my MB Air. Basically, the HD was attached via usb drive and played videos. The problem is the HD basically failed in less than 3 weeks. Now it does not mount 90% of the time. The other 5% it would mount, however it would make a ticking sound, and the rest of the 5%, it mounts and I can pull videos onto my Air's main HD, but it usually fails after a few Gigs of transfer video. My question, Are portable Harddrives not meant to stream data like watching videos? I have a custom 60gb portable HD that used my old Ibook 60gb HD and I've had that for years and never experience any issues. In fact I still have it and use it to back up my Air.