Yes...but not as you'd expect. I use the Kingdoms of Khalamar screen as my primary reference. I don't have it open as a screen to roll dice behind, I just have it at hand as a reference.
When I need a "secret result" say for a search or spot roll, I roll 2 d20s, both of them different colors, and in my head I simply choose a color for the day before the numbers are generated.
For combat, rolling the dice in front of the players just seems to add more tension to the melee.