The current beta build of Valve's Steam client allows users to remotely manage their game library from a web browser.
The update means users can remotely start downloads on their home PC. It's a welcome addition, though it isn't perfect; your PC must be on and logged in to Steam at all times, meaning it's not quite as convenient as it could be. Some kind of wake-on-LAN support would be ideal.
The latest beta also fixes an issue that caused too much memory to be used while downloading game updates, and adds debug code to help diagnose problems with file downloads. For more, follow the source link below.