This or a variation of this would probably be the best option. Carrying the SCR file on a thumb drive or copying it from one drive to another would be the way to go. I do not understand how this would go haywire for you? I use the sneaker network method between two satellite computers and a network solution on two computers at home. Since SCR files are actually packages if you do not zip them prior to “syncing” you may run into a few snags or even file corruption (See this thread Working off of network drives (MobileMe, thumb drives...) )
Can you go into a little more detail why the USB thumb drive method is not working? Maybe we can address that and get things going smoothly without getting to technical.