The OA comment of "EBS snapshots cannot be moved between regions" should have "easily" inserted in there. I've seen quite a few full length processes for doing it, e.g:

http://elastic-security.com/2011/02/10/how-to-copy-an-ebs-ba...

http://serverfault.com/questions/336321/how-do-i-migrate-ama...

I'm 95% sure they are just putting a UI over that lengthy process. But as I say, I've tried it and it worked perfectly for me. This is their process:

http://blog.ylastic.com/migrating-snapshots-between-ec2-regi...