I have a macbook, and it only has 2 USB ports. My SuperDrive broke, so I have to use an external since I'm still a student (so I have an extremely tight budget). I have to use it to boot from the Mac OS X install dvd, so that's both my USB ports gone right there. And my Time Machine backup requires another USB port (since a Wifi drive is too expensive for me). Any way to have both of them running at the same time? I'm kind of a n00b at this.