anyone know what the memory and HD limit i can upgrade this machine to? thanks!
It can take two 1 gig PC5300 SO-DIMMs and it can take a 500 gig hard drive internally (the largest currently available), and a hell of a lot larger than that externally. I have two 1 TB drives connected to mine. A firewire media drive and a USB Time Machine drive.
If you want to hack it, you can attach an internal SATA cable to an eSATA port out the back, and connect it to a 1 TB 3.5" eSATA drive. Of course, you lose your internal drive doing this and you'll only get 1.5 gbps, since that's what the controller can do.