This is something I've thought about for a while. If you find something you're comfortable wearing and eliminate the "what am I wearing today?" process from your daily routine, your mind is that much more engaged in thoughts that matter.
I used to feel the way you do, before I met my girlfriend and saw myself through her eyes. She felt about my graphic tees and ill-fitting pants the way I did about her MySpace page's design.
I realized that what you wear affects people offline about as much as your webpage's stylesheet does online. It shows your creativity, attention to detail, and sense of design, or lack thereof. What you're wearing is already influencing what people think of you, whether you choose to acknowledge it or not. As with all those local businesses that don't think about their website.
It only matters if you care what other people think. If you can afford not to, or only interact with people virtually, great. But, whether you care or not, if you wear clothes that don't fit or the same outfit every day, people will probably think you have no taste/money/fun. There's a reason Steve Jobs used to dress like this:
You can bet he dressed differently at the Homebrew Computer Club meetings. And nothing wrong with programming in only a towel. Fashion is dynamic. Yes, it's just personal styling, but it's no more "superficial" than your CSS. Wearing a black or white t-shirt/polo/button-down and jeans/khakis is like using the default Wordpress/Posterous theme on your blog.
Does it really take that long to decide what to put on? Vint Cerf found time to dress with style and still invent the internet.
There's a reason software hasn't eaten politics, law, finance, apparel, and hospitality yet. Indochino and Airbnb are certainly a start with the latter two, and no surprise, they dress with style when appropriate[1][2].
