Yes, I have one just like the one pictured in the OP. I use it mainly to grind up cloves when I make chili in the winter. (We used to have them in the hospital but I haven't seen one in a while - now we have disposable pill cutters/crushers.)
My DH has one from Crate and Barrel and loves it! Uses it all the time. We also gave one as a gift to our neighbor who is a cook and he tells us constantly that it was the best gift he's gotten!
I have one and I use it a lot for grinding spices and also for grinding salt to make it super fine so it sticks better to fried foods.
When my niece and nephew are visiting, they like to "help" in the kitchen by using it to grind up spices too. They like to go through my spice cabinet and sniff everything, then put thier combination into the mortar and grind it up.
I have a mini one that I bought in the grocery store several years ago. For some reason, I always wanted one. I think I used a few times right after I bought it, but I haven't for a long time now. I guess I don't cook that much any more.
Yes, we own about 7 or 8. Of course, DH is a pharmacist, so that's why! We have tiny wooden ones, a couple brass ones, and a huge one that ways a LOT! I don't know what it's made out of, but it's really neat looking.