How to give file sharing permission to a specific user over lan??

I have a home network implemented using workgroup. I want to share a folder on my vista pc with one other user over lan. I want to set it up like if that particular user clicks on the folder (under "Network"->"My PC"), he gets access, but if some other lan user clicks on the folder, it prompt for a password OR give any kind of error.
So far I have tried going to to-be-shared folder's security permissions and grant "Everyone" read persmissions, but then everyone over lan gets access to the folder contents. If I remove everyone, then that specific user I want to share folder with also gets blocked out. So far its all-or-none results for me. Someone suggested me to create a local account on my pc with the same username as the friend I want to share folder with, but thats little clumsy stopgap solution for me because then I would have to create a user on my pc for every person over lan who I want to share a specific folder with. Is there any other way to accomplish the desired results??

there are a couple of ways you could make it happen but they all involve extra time and or money:
1) set up as NAS system some of the like the buffallo drive will allow you to create users to access network resources

2) use a open source ldap implentation to create a directory

3) set up a win srv 2k3/8 directory

without a directory there is no way to centerlly manage users and ressouces thats why setting

a cheap way would be if you have a extra pc and a large HDD you can´store all the profiles and shared folders on this pc