Primary Keys: IDs versus GUIDs

I need to get a life. This actually made sense to me:

Coding Horror: Primary Keys: IDs versus GUIDs

...You can generate IDs anywhere, instead of having to roundtrip to the database...

The article, comments, and links are a good mini-tutorial on a relatively esoteric aspects of managing data -- how should one generate a unique identifier? This one advantage solves a problem for my work life ...