Sharing projects between computers

Hi
This is my first post, and I'm new to FCPX and have limited experience in previous FCP, so please bear with me!
My colleague and I are both working on a project, and it would be great if we could "pass" it back and forth between us. What's the easiest way to do this? We each have an 8GB Macbook Pro and both have up-to-date FCPX, and our footage is backed up on a NAS server. Surely if we each have a copy of the footage on an external HD with the same filenames we should just be able to give the FCPX file to each other and reconnect the media. For some reason this isn't working. Am I just being dumb? (No one word answers please, despite the temptation!)
Thanks in advance

Very simple. Only move the "Currentversion.fcpproject" file from the Project folder. You can move older versions for archiving in to another folder. MacBreak Studio has a clip about doing this somewhere.