Running Version
Microsoft SQL Server 2000 - 8.00.534 (Intel X86) Nov 19 2001 13:23:50 Copyright (c) 1988-2000 Microsoft Corporation Developer Edition on Windows NT 5.0 (Build 2195: Service Pack 2)

I did run the sp_spaceuse from the two different databases with the folloing results

Name Size Unallocated
Master 33.00 MB 3.87 MB
Pubs 33.00 MB 19.14 MB

The reason that I want a new sp is that I wanted the result set store in a database table for analysis