OneAndOneIs2

Having been held up in getting email posting sorted out because I didn't know
the ID no. of the default category (14 - what's the logic here??) it
leads me to wonder: Just how useful are categories?

Or, more to the point: How desireable are categories?

I haven't bothered with them, and just file everything under a catch-all "Omni"
category. I never bother with categories myself when visiting a blog - either
I'm interested enough in what a blogger has to say that I read all the posts,
or I tend not to read their blog at all.

But that's just me. Are there people out there that find categories worth
having?