Where can one view a list of available toll-free 800 numbers?

One can look up toll-free 800 numbers at TollFreeNumbers. Their Instant 800 Lookup can check specific numbers quickly and easily and the number will come back "in use" or "currently available". For any number that says "currently available", it can be instantly activated. The toll-free codes in North America are 800, 888, 877, 866, 855, and 844, with 833 and 822 reserved for future toll-free use.