Oscar doesn't get on my desk, or even sit on my lap when I'm at the desk.
Honestly, that's fine with me.  My desk is covered in papers, and I get pretty
intense about some computer activities, like coding and playing games.

My desk is built such that there's a gap between the "main" desk and the
"monitor stand" part of the desk.  That gap was just the right size for a
certain kitten to use as a "safe spot."  Then, when I would go to do something
at the computer, this certain kitten would feel threatened and hiss, claw and
bite at the hands of her "invader."  Well, I'm happy to give Oscar more than
her share of the bed or almost any other place she wants, but dammit, THE DESK
IS MINE.  I wasn't willing to be evicted from my desk by a 4 month old kitten.
Nothing like having several people in an online game relying on you to do
something when your cat lashes out, scratching your hand and simultaneously
ruining several hours of planning.

She does like to lie down by my feet while I'm at the desk, though.  It's fun
to give her backrubs with my feet, but I do worry that I'll accidentally hit
her with the chair rollers some time.