How to use external HD to store data on from a windows PC and Linux PC Simultaneously

[Hard and Confused]

Just curious if anyone know how to setup a system to allow a Windows based PC and Linux based PC to simultaneously use an external HD to store data on.

 

[aubsxc]

The drive would be physically connected to one machine and set up as a share so it could be accessed over the network by the other.

 

[Hard and Confused]

Hehe, there is no network but that is about to change I think with a USB to NIC adapter for the linux based DVR and an ASUS router that allows 2x USB hard drives.