Glass Salt Pepper

What are these little bowls called?
When cooking, there are these little glass or other material bowls that you can put salt, pepper, and other stuff that helps you get everything measured out and ready to go for when you cook. What are these things class I am looking to get a christmas gift for someone. Thanks!
They’re prep bowls! I love them! they make everything much easier
http://www.williams-sonoma.com/products/sku8739781/index.cfm?pkey=xsrd0m1|16|||0|||||||prep&cm_src=SCH
Amazon has lots to pick from!
http://www.amazon.com/s/ref=nb_ss_gw?url=search-alias%3Daps&field-keywords=prep+bowls&x=0&y=0