3. VPN access and logmein have a delay.
What type of delay would be acceptable to you? only if it is as fast as being right there in the office? or can you put up with slightly reduced performance? The solution for you will depend on your pain threshold for delay.
Using a single, central source of data is the best bet. Sync and the manual movement of the database are lessor options than real time remote access of your database at the office. All it will take is once to delay reinstalling the database and your front desk will schedule patients or do other work in the database without your updates -- giving you a painful out of sync situation.
Several remote access options have been documented on the forum. Here I believe is the list of those mentioned to date:
1. UltraVNC
http://www.uvnc.com/2. Remote Desktop Connection
http://www.microsoft.com/windowsxp/using/networking/expert/northrup_03may16.mspx3. GotoMyPC
http://www.gotomypc.com4. LogMeIn
https://secure.logmein.com/home.asp?lang=en5. VPN routers and other hardware based solutions
<urls being evaluated-will post later>
I'm in the process now of doing a detailed review of each of these remote access options and evaluating tradeoffs for speed, security, features, and cost. I'll be sure to post my findings with a follow up postings and experience reviews on each method.