Long cable

Fo the Ethernet cable can you buy any ehernet cable or you have to use the one with the xbox360 and another question what do 50' mean?

Yes, and the ' means feet. So it would be a 50 foot cable.

 This, of course, only applies if you are American. =P

so can you use a different one

Links14

Yes you can, go here to buy some, http://www.netcablesplus.com/index.asp?PageAction=VIEWCATS&Category=60 they have all different lengths at really cheap prices