Yes, you can in both XP Home (Strange) and Pro and I have done it.
Run the New Connection Wizard and click "Next"
Select "Set up an advanced connection" and click "Next"
Leave "Accept incoming connections" selected and click "Next" twice
Leave "Allow virtual private connections" selected and click "Next"
Select the user accounts to allow in and click "Next" twice (Windows will use the XP login name and password for VPN)
Click "Finish" and set up a remote connection
I have one problem with this method: I can no longer browse the web when connected! This is a "security feature" that cuts off the rest of the world when using VPN. This sucks because I want to use VPN primarily to get an IP address from home for browsing through my home connection. Oh well, that what I get with a free VPN server 🙂