Can I transfer xbox 360 game save data to another system and continue playing the game on both systems?

My brother and I have been playing GTA 4 on one system, both have separate game saves but play under the same system profile. He not has his own system. How can I copy the game save data and continue to play on my system as well as his system? I do not have consistent access to xbox live so any transfer method relying on that will not work.Can I transfer xbox 360 game save data to another system and continue playing the game on both systems?If he has his own gamertag on the other console, then I'm pretty sure it's not possible. If he's playing under the same name, then you could just save his game to a memory card instead of the hard drive and then load that on the new one.