Unless I'm horribly mistaken I don't think that's correct. I don't believe you can take two completely independent copies of the same workbook, give them to two users remote from each other and expect to be able to merge them when they are returned.

Workbook sharing implies sharing the same workbook on a network - see the MS article http://office.microsoft.com/en-us/ex...001013057.aspx

Of course it only works with shared workbooks as you said, that's the whole point. The operative word is 'shared' (implicitly on a server). Merging, in the sense of bringing together completely separate instances of the workbook does not apply.

Regards