How to lock file system access

Hi Everybody..

I am using Moblin V2 which has nautilus file manager the one which is also used in Ubuntu.
I want to lock the access to file system such that i can only browse my home folder not other locations like /, /usr, /bin and all.

Or i want to create a partition of 10 or 15 GB so that i can only browse this partition not other folders of filesystem.

Thanks Guys.. waiting here for ur response..
Lokesh Singla

Double post. Continued here