>Given, however, my natural curiousity regarding the API, I'd be interested in
>knowing how "unique" keys generated with CoCreateGuid() would be. Of course, it
>might be difficult to ascertain, and certainly (I don't think) could be done on
>a single machine.

If I understand correctly, CoCreateGuid() keys off the MAC address of the Ethernet card, if one exists, and is therefore guaranteed to be unique between machines with cards. Within a machine, I suppose you could defeat it by resetting the system clock, and running it at exactly the same time.

As I understand it, if the machine doesn't have an Ethernet card, it uses some other algorithm that is unlikely to produce duplicates.

BTW, the Identity columns in SQL Server 7 are supposed to be GUIDs, so that every row is unique globally, not merely within a table.