Some good advice. Showers are important, but I'd like to believe that software is a place where a programmer (who doesn't go face-to-face with clients) could wear a mohawk for three months. I'm an idealist.
Tolerance for radical style choices are one thing but unfortunately in IT circles, it's all too common to have people that have no sense of basic hygiene at all. If you constantly wear dirty (maybe also worn-out?) clothing, smell like the dead and your hair's always greasy, it is bound to affect what people think of you. I don't think that there are many places where unshowered folks automatically mean good code.
Personally I screen out all the companies with smells like that - not because I like to wear a mohawk (I am a huge nerd but I love wearing a suit and tie) but because it tends to be the kind of place were people judge you on how you look rather than what you do.
Beware thinking that environments where people don't dress formally are environments where people don't judge based on looks.
I don't love wearing a suit and tie, but do it for my day job. If I go to a tech meetup after work while still wearing my day-job clothes, I find a lot of people judge me to be someone not technically serious, based on how I happen to be dressed at that time. Prejudice based on appearance is a cognitive shortcut lots of people overuse.
There are places you can get away with it, but the industry as a whole is still very business-centric. I've heard of places were people are required to wear slacks everyday.
Until I left, my previous company's policy were shoes (not sneakers, or black sneakers), collard shirt (right now your thinking polo!.. but read on), tie (yeah, so that nixes the polo), slacks. On Fridays, you get to take off the tie.
Come to work without a tie? Go back home. I always kept a backup because sometimes you forget!!!
I think it depends a lot on the reputation you build around yourself.
Ever noticed how the design/artistry department gets away with looking all sorts of crazy creative? If you convince people around you that you are crazy creative then you get to dress pretty much any way you want!
Of course this must not be a show you put on, you must always be like this.