In reply to Dominicandave:
Sorry to put a downer on things but there is a cost to the company of giving you a chance to prove yourself even if they don't pay you.
Hiring staff costs time, effort and money, if they take a risk on you there is a large opportunity cost that comes from not hiring someone who passes their normal hiring procedures. Also why would they want to deviate away from what they believe is best practice in their hiring procedure? another risk.
That said it depends on the company, smaller one man bands are much more likely to be flexible than big bureaucratic ones and so may listen to your idea.
My advice? Research. Know the ins and outs of the company, learn about their products and their methods of doing business. Learn about their competitors, their products and their methods of business and think about how they are different (and the same). Rehearse your answers for questions like 'why do want to work here? tell me about a time when you showed leadership, solved a problem..'. Know your CV back to front focusing more on perceived weakness over strengths.
Post edited at 13:14