*** Bug 15125 has been marked as a duplicate of this bug. ***
In addition to using the grid layout example as proposed by Tab, add the suggestion from Hakon in the original email:
Added code sample as proposed by Tab and added suggestion from Hakon on region styling:
Paris F2F - make region 4 the "catch all" region that will be used to hold any overflowing content.
Layout (using grid) was added to the current spec. editor draft.