You can share the hdd and files of your Personal Computer and other Vu+ box's with your PrismCube via samba.

1) Make sure that samba is up and running in your Vu+ box and your Personal Computer
2) Goto Xbmc -> System -> File manager
3) Click on Add source
4) Click on Browse
5) Select Windows Network (SMB)
6) Select the group the device and the folder you want to mount
7) Optionally change the name with your favorite chosen name
8) Click ok

All done.

If you would like to have your devices under the section Video and Movies too you will need to repeat these steps in:
1) Xbmc -> Videos -> Files -> Add Videos
2) Xbmc -> Music -> Files -> Add source.

Thx Shiro