Fibs challenge

program which will:
Display the largest fibs you can in your language of choice, but using only your own code
(no non-standard libraries like multiple precision arithmetic).

I wrote one in C++ that displayed one infinitely large(not really, but I easily got it to display a Fibonacci number that was 700,000 digits. I did it by making a new class bigInt, that was a string. I overloaded all basic operators needed to calc fibonacci and then just wrote an iterative fib function. I'll try to dig it up.