Do many people have these? If so do they have much use? I was considering one because I will be playing on my mates 360 a lot soon but want to bring the achievements across to my profile. So how does this work, you can save your profile to the card and any achievements go straight on? Or I put my save games on the card then load it on my own 360 for points to get added? *Is it the exact same as using any USB stick? Does the 360 unit offer any benefit?