Working in the software biz, I'm used to shorts and t-shirts when I've worked in software companies, or khakis and button down shirts (or jeans and polo shirts for casual Friday) when I'm in a corporate IT environment. When I worked in consulting, it was usually shorts & t-shirts at the office with dressing up when I had to visit a client's office or go out to lunch or dinner w/ clients. I do have a sizable collection of ties, dress shirts, etc, but those mostly only are for formal events. I would never go out in public in flip-flops, pyjamas or sweatpants, though...some clothes are only good around the house.