Sure. Right click on the folder, select sharing and security. Share the folder and click on the button that says "Permissions." click on the Add button and it should pop up a window that has a box where you can type in the names of whomever you wish to access the folder/files. Normally this only pulls info from Users/Groups/and something else, but if you click on the button that says "Objects" you can specifiy that it should include computers in the list as well. anyway, enter the FQDN of the computer (or IP address) that you'd like to have access to the data and then click on "Check Names." It should find the computer and everything should be good. Once you are done with that, you should be back at the window where teh "add" button was. Select the computer you just added and set the permissions as you see fit.
Of course, this is assuming you are using Windows XP Professional, and have the computers as a member of the same domain.