My employer uses the Cisco VPN for remote access, but the VPN server version we use has been End of Lifed by Cisco and won't be coming out with a native Windows 7 64 bit version. Since purchasing a new server would be a significant expense they are holding tight with the deprecated version. So we're making due with the Cisco VPN Client version 5.0.6.0110. This raised a concern that as people replace their old home computers with new ones they will be getting Windows 7 64 bit machines and therefore not be able to use the VPN.
Because 64 bit is required to support more than 3G of system RAM pretty much every machine you can buy today not only comes with Windows 7, but 64 bit Windows 7.
When I bought my new machine I upgraded from Windows 7 Home Premium to Windows 7 Professional so it would have the XP Mode feature. It doesn't come installed on the machine, you have to download it from Microsoft and install it.
Once you have XP Mode installed you have to configure it to give the virtual machine it's own IP address instead of sharing the network adapter with the host operating system (Windows 7). At this point I would recommending installing all Windows XP updates through Windows Update. Once you are fully caught up I would recommend shutting down the XP Mode virtual machine and making a copy of the disk image. You can then set up the copy as a seperate virtual machine that you will be using for VPN access and still have a "clean" XP Mode for anything else. Once you set up the dedicated VPN machine you can install the Cisco VPN client and have it isolated from everything else on your machine.
Since I've had times in the past where the Cisco VPN Client freaked out and ruined the networking on my XP machines I ended up liking the virtual machine solution because I can back up that image and restore it in case of trouble. If I were running security at my company I'd like the virtual machine solution because I've effectively dedicated a machine for remote access that I use for nothing else. Running XP in a window of a fast machine has perfectly acceptable performance and can be maximized to full screen.
The only downside is that this solutions requires an upgrade to Windows 7 Professional which is not otherwise needed for most home users, and that upgrade costs about $100.