Yup, you can "turn-on" IIS in WindowsXP and use it to host both a FTP and Webpages. Go to Control Panel, select Add/Remove programs. Click on Add/Remove Windows Components. Find "Internet Information Service (IIS" in the list, click on it, select Details, and select the services you want to enable. You can then use a Dynamic DNS service such as No-ip.com so that when/if your IP address changes, your friends can still find your site.
If you are not familiar with setting up IIS you can use the Windows Help, and the many various tutorials around on the net for further information.