Valve has officially launched the new remote download feature for all Steam users after an obviously successful beta test.
A new Steam client will download upon logging into the service that enables the feature. You can set a download running on your PC at home via your mobile’s web browser and the Steam Store. The feature also allows you to re-download past purchases and have them installed for when you get home. This is definitely going to lead to a lot of spontaneous purchases during the commute to work.