>>I can't think of a good reason to use a character data-type for a surrogate primary key. The integer data-type seems particularly well suited for surrogate primary keys, and you can always STR it if you need to concatenate it with another field. Using the STR of a numeric value for the key itself seems like unnecessary overhead.
>
>Then, what about using GUID ? It's character type and it's BIG - 38 char long...

Nick,

Nope, a GUID is a 16 byte integer. From the Platform SDK - COM:

"CoCreateGuid - Creates a GUID, a unique 128-bit integer used for CLSIDs and interface identifiers."