Windows only HFS (HTTP File Server) offers a super simple way to share files via the Internet. There is no install, simply an .exe file (550KB!) that provides an "easy" mode for most users and an "expert" mode that offers advanced preferences for the brave. To share files through HFS, either drag/drop the files to the HFS window, or use the Windows Explorer integration with a right-click. You can add user accounts to HFS so that you can access your own files while not at your computer, or let your friends download the latest killer track you recorded in Windows Sound Recorder.

Once you get HFS configured the way you want it and have configured a port forward in your firewall for port 80 (if your ISP lets you host on that port), just have your friends use their favorite web browser to go to your public IP address or dynamic DNS hostname like http://downloadsquad.no-ip.com and they can log in and download your shared files. You can customize the web page that your visitors see, and you can monitor connection information like what IP is connected, what is being downloaded, etc.

[Via Brown Thoughts]