Well, if you encrypt them, they can see there's a file called foobar.jpg -- but they won't be able to see the contents. Now, if you use something like Jetico BestCrypt or PGPDisk, you can create an encrypted container on your harddrive and store files on it. That way, someone browsing your harddrive seens "container1.enc" or whatever, of size 20GB, and has no idea what's inside.
Then, you store all of your files on there and you're set. Otherwise, I'm not sure I can come up with a good solution for you
