No strong opinions, I like guids because I am not dependent on a system table to provide information for my key, it is all procedure driven. Nice when you are working with disconnected datasets, such as in a web environment.

>>I think of a customer entered key, much as I would a first name. Good information, but not something you can rely on. Useful for searches, but not a guarentee to find what you are looking for. I use GUIDs for my pk's. Love them.
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>GUIDs of course solve the problem of creating PKs for computers which are not always connected. I was thinking about the following alternative, but never actually tried it: assign each branch office a different number, and create PKs like: bintoc(branchnum, 2) + bintoc(SerialNumber("TableName"))
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>... where SerialNumber() gets a sequential number from a special table.
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>This would use 6 bytes, instead of the 16 used by the GUID. Any opinions?