Later this week Valve Software, makers of the popular Half Life series, and the Steam software distribution system are releasing the first version of the Steam Cloud service in the demo for the upcoming cross-platform title Left 4 Dead. The service will keeps things like game saves, mouse and keyboard settings, and player profiles the same across multiple PCs.
Up until now the Steam application, which lets you use the same game license on multiple computers, required users to take and make these changes across all their devices., Steam Cloud puts the onus on Valve instead, and syncs up any per-game settings changes between sessions.
In addition to the Left 4 Dead demo, which will be available this Thursday, Valve is adding Steam Cloud functionality to its entire back catalog of games, making it easier to ferry settings back and forth in case you have multiple gaming rigs. No word yet on when you'll be able to do this with (now) classics like Portal and Half Life: Episode 2.