Job interview!

Wow. Today I've got a mail asking me to call them in order to fix a date and time for a job interview.
I'm not sure if this is from the same people who called me a week ago. If it is from them, this actually take the meaning of the infamous "manana country" to new lows. If this is for another job aplication that I did over the web... well, this is even better!

Anyway. I've just called them and I've got myself a job interview for tomorrow. Now, the question is: what should I wear?