I found a program called NoSleepHD that's made to prevent harddrives going into sleep mode, but it will only work if you have the drive connected to your PC (I emailed the designer). What it does is write a blank text file to your harddrive every X amount of minutes. Then it just keeps re-writing the same file, so it takes up almost no space at all. This seems like a pretty easy thing. Is it possible to have something like this coded in homebrew?