Shared Workbook Alternatives

I need multiple users to share the same workbook, but the shared workbook functionality in Excel seems surprisingly limiting. For example, I would like the automatic updates more often than every 5 minutes. The other option is to get updates after the workbook is saved, but if one of the users wants new updates they have to wait until the other user saves their file...you would think one user would have some sort of option to get the other users changes without saving/opening/closing the file.

Anyway, there must be some alternatives or better ways to have multiple users share a workbook on a network. Some thoughts I had were (1) a macro that saves after every workbook change (2) a looping macro that automatically updates every 10 seconds ....what are your thoughts? How can we make the file as real-time as possible, so as soon as one person makes an update, the other person can see it. There will be NO OVERLAPING CELLS!

D