Limit file access between accounts?

Absolutely it is. Mac OS X defaults to having things outside your main user's Public folder (and folders you create at the user folder level, unless you manually change the permissions) inaccessible to other users.

 

Yeah, just go to System Preferences > Accounts, unlock it to make changes, and click the + under the list of accounts on your system.

 

This is not the case.

If you want to limit access to others on the same machine use 'Get Info' in Finder and make the appropriate changes to the 'Sharing and Permissions' section. You can make changes to all enclosed items using the gear pulldown.

I'd suggest experimenting on some files and folders to make sure the effect is what you want.

A.

 

AFAIK, unless someone has changed the permissions on your desktop folder, even another Administrator account shouldn't have access to it.

I just created another Administrator account, and when I logged on with it and tried to view my normal account's home folder, I could see that there's a desktop folder, but I had no access to view what was on it.

You'll need to right-click on your Desktop folder (logged on as you), Get Info, and check the Sharing & Permissions area at the bottom. Mine says that I have Read and Write, and Everyone has No Access.

If yours is set differently, try setting it to that and see how it goes. Same idea for your external drive.