"Now, I am really raising two separate issues here. On one hand, I am talking about syncronising two separate computers and on the other, I am talking about a seamless experience between online and offline applications. I think the first is mostly being taken care of. The second issue has some solutions becoming available also. This is where I see stuff like Google Gears, Adobe Air and db4o especially their db4o replication system proving to show their usefulness."
http://www.opensourcetutor.com/2007/10/09/seamless-onoffline-design-winforms-and-deploy-as-ajax-webapp-on-mono/