Since having been moved into a cubicle, however, where I am visible less than half the time, only seen when I go get a free drink from the fridge, use the bathroom, or take a walk outside, I have been dressing much more casually.
Decent shirt, but probably less than business casual, sometimes as casual as a Pink Floyd or a shirt that I got at a concert. Jeans. Sneakers. Summer=shorts. A lot of times, I'll just find a nice casual shirt and wear it for 3 or 4 days if its fairly clean. Clothing is just the last thing on my mind when it comes to getting dressed in the morning. I know I have to do it in order to go out into the world, but I don't really care what it is.
Of course, my supervisor does warn us if corporate is coming to visit for the day, for which everyone tends to be even more dressed up than usual. But that is just the way our office is. I've worked around the United States.. it seems like the East Coast and Midwest are slightly more strict in wanting people to dress business casual, and be clean-shaven, while the West Coast and Mountain areas are more lenient, and doesn't even seem to mind a mustache or beard, though either should be somewhat groomed.
East Coast/Midwest: tattoos should be covered. West Coast/Mountains: tattoos are okay as long as they are not offensive.
Just today, I walked into Walmart, and a guy who looked like the manager is loaded up to his neck in tattoos. I don't remember ever seeing that when I lived on the East coast.