If you don't use terminal services in one form or another, you increase the
chance of corruption, and you slow the application performance to an
unusable level. It is possible, but you really need to do it over a terminal
server connection. You can (and should) use a VPN connection for the
terminal server, in which case the front-end also resides on the server.
Multiple users should each have their own front-end, in their own folder, on
the server.
For a single user (or 2), with admin rights, you can use the built in
Terminal Server RPD connection. That's not very secure with 2 users being
admins, so you may want to use a Windows Terminal Server, a Citrix Server,
or to save money, WinConnect.
http://www.microsoft.com/windowsserver2003/technologies/terminalservices/default.mspx
http://www.citrix.com/lang/English/home.asp
http://www.thinsoftinc.com/