ClickOnce.... Easy Deploy of MS Windows Forms Based Apps

ClickOnce is a new application deployment technology that makes deploying a Windows Forms based application as easy as deploying a web application. With ClickOnce running a Windows Forms application is as simple as clicking a link in a web page. For administrators, deploying or updating an application is simply a matter of updating files on a server; no need to individually touch every client.

ClickOnce applications are fundamentally low-impact. Applications are completely self-contained and install per-user, meaning no admin rights are required. You don’t have to worry about a ClickOnce application breaking other applications.

http://msdn2.microsoft.com/en-us/netframework/aa497348.aspx

ClickOnce Team Blog: 
http://blogs.msdn.com/clickonce/