The next big thing in remote networking is the little known feature of Windows 2003, and therefore SBS2003, Network Quarantine. Start reading up on it now because ISA 2004 is coming soon and it makes implementing this feature a whole lot easier. Master this feature now because there is more to come with Longhorn. In that Windows release you'll be able to quarantine local PC's too. For clients with roaming users like real estate agents and sales staff this is a sorely needed feature. In the meantime we can at least quarantine computers coming in over VPN.
What is network quarantine? Network Quarantine allows you to specify that incoming VPN connecting computers sit in a safe sandbox until they meet certain standards for virus protection and patch level. Several of my small business networks include remote offices with computers that VPN into the main office. Now we'll be able to check out those computers before letting them into the SBS server.
Network Access Quarantine Control in Windows Server 2003
Get it Here
Support for the Windows Server 2003 Network Access Quarantine Control feature in ISA Server 2004