There has been a lot of discussion on website, blogs, email, tweeting, etc. on "Cloud computing". So what is "cloud". Basicially it is web-based vitual server space and applications. Instead of building on-site server rooms, servers, and the high costs related to that, its all gone virtual. In a simple form its like Web-mail, Flickr and Google Docs. These are all a software service, on the web. Autodesk is working on something similar for the cloud, which is project Butterfly. Online drawing without the need to buy/install an application. Multiple users drawing in the same drawing at the same time.
Microsoft has more information on cloud computing: http://www.microsoft.com/cloud/