If only people would be grouped by decades, ie 90's kids. The problem with this though is it doesn't mean you were born in the 90's, but you grew up on the 90's - but what age is growing up?
Regardless, although I understand the ubiquity of terms like millenial, I think there's so much more value in breaking down things into decades. I'd actually say 8 year segments are the most useful because you can use presidents (who often serve 2 full terms) as references, but that's specific for the US and doesn't jive well with a base-10 counting system.
I bet out there somewhere someone has come up with a great way to classify generations specific to cultural changes and I just haven't found it yet. Maybe it'll show up in this thread.